Medicine guide

Losartan Potassium and Hydrochlorothiazide

100 mg + 25 mg · Tablet, Film Coated

Prescription only
Angiotensin 2 Receptor Blocker

Active substance: Losartan Potassium and Hydrochlorothiazide
Used in: Heart, blood pressure and circulation
Made by: Proficient Rx LP
Source: Official label

Quoted from the official source. Not yet reviewed by Mediclarum — the leaflet in your pack is authoritative.

At a glance

Quoted from the official label · 2023-08-01

What it is

Angiotensin 2 Receptor Blocker

Used for

Hypertension Losartan potassium and hydrochlorothiazide tablets USP are indicated for the treatment of hypertension.

The label’s usual adult dose

Losartan can be administered once or twice daily at total daily doses of 25 to 100 mg.

The maximum dose is one tablet of losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg once daily.

Full directions ↓

Serious warning

When pregnancy is detected, discontinue losartan potassium and hydrochlorothiazide tablets as soon as possible.

All warnings ↓

Good to know

Prescription only
FDA enforcement reports list no ongoing recall, and none from the last two years, for this product code · checked 2026-10-02

80other products contain Losartan Potassium and Hydrochlorothiazide — compare makers, forms and strengths

Every line above is selected, not written, from the official label. Nothing is reworded. DailyMed

What it is for

Hypertension Losartan potassium and hydrochlorothiazide tablets USP are indicated for the treatment of hypertension.
This fixed dose combination is not indicated for initial therapy of hypertension, except when the hypertension is severe enough that the value of achieving prompt blood pressure control exceeds the risk of initiating combination therapy in these patients (see CLINICAL PHARMACOLOGY , Pharmacodynamics and Clinical Effects , and DOSAGE AND ADMINISTRATION ).
Hypertensive Patients With Left Ventricular Hypertrophy Losartan potassium and hydrochlorothiazide tablets USP are indicated to reduce the risk of stroke in patients with hypertension and left ventricular hypertrophy, but there is evidence that this benefit does not apply to Black patients (see PRECAUTIONS , Race ;
CLINICAL PHARMACOLOGY , Pharmacodynamics and Clinical Effects , Losartan Potassium , Reduction in the risk of stroke , Race ; and DOSAGE AND ADMINISTRATION ).

From the official label · 2023-08-01 · DailyMed

How it works

From this product’s own US prescribing label.

Angiotensin II [formed from angiotensin I in a reaction catalyzed by angiotensin converting enzyme (ACE, kininase II)], is a potent vasoconstrictor, the primary vasoactive hormone of the renin-angiotensin system and an important component in the pathophysiology of hypertension.
It also stimulates aldosterone secretion by the adrenal cortex.

Peak level after1 h

Half-life2 h

Mostly cleared after≈ 10 hfive half-lives — our arithmetic

The shape is a standard model drawn from the two times above, not a measurement. How fast a medicine acts and wears off also depends on the dose, the form and the person.

How the body breaks it down

Hydrochlorothiazide is not metabolized but is eliminated rapidly by the kidney.

How it leaves the body

When losartan is administered orally, about 4% of the dose is excreted unchanged in the urine and about 6% is excreted in urine as active metabolite.

With food

A meal slows absorption of losartan and decreases its C max but has only minor effects on losartan AUC or on the AUC of the metabolite (about 10% decreased).

Quoted from the prescribing label, sections “Mechanism of Action” and “Pharmacokinetics”. DailyMed · 2023-08-01

Serious warning

The strongest warning the FDA requires. It is printed in a box at the top of the label.

FETAL TOXICITY
When pregnancy is detected, discontinue losartan potassium and hydrochlorothiazide tablets as soon as possible.
Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus. See WARNINGS, Fetal Toxicity.

Quoted from the official label, section “Boxed Warning”.

Do not take it if

Losartan potassium and hydrochlorothiazide tablets are contraindicated in patients who are hypersensitive to any component of this product.
Because of the hydrochlorothiazide component, this product is contraindicated in patients with anuria or hypersensitivity to other sulfonamide-derived drugs.
Do not coadminister aliskiren with losartan potassium and hydrochlorothiazide tablets in patients with diabetes.

Quoted from the official label, section “Contraindications”.

How to take it

These directions are for this exact strength and form. Another one is different.

Hypertension Dosing must be individualized.
The usual starting dose of losartan is 50 mg once daily, with 25 mg recommended for patients with intravascular volume depletion (e.g., patients treated with diuretics) (see WARNINGS , Hypotension — Volume-Depleted Patients ) and patients with a history of hepatic impairment (see WARNINGS , Impaired Hepatic Function ).
Losartan can be administered once or twice daily at total daily doses of 25 to 100 mg.
If the antihypertensive effect measured at trough using once-a-day dosing is inadequate, a twice-a-day regimen at the same total daily dose or an increase in dose may give a more satisfactory response.
Hydrochlorothiazide is effective in doses of 12.5 to 50 mg once daily and can be given at doses of 12.5 to 25 mg as losartan potassium and hydrochlorothiazide tablets USP.
To minimize dose-independent side effects, it is usually appropriate to begin combination therapy only after a patient has failed to achieve the desired effect with monotherapy.
The side effects (see WARNINGS ) of losartan are generally rare and apparently independent of dose; those of hydrochlorothiazide are a mixture of dose-dependent (primarily hypokalemia) and dose-independent phenomena (e.g., pancreatitis), the former much more common than the latter.
Therapy with any combination of losartan and hydrochlorothiazide will be associated with both sets of dose-independent side effects.
Replacement Therapy The combination may be substituted for the titrated components.
Dose Titration by Clinical Effect A patient whose blood pressure is not adequately controlled with losartan monotherapy (see above) or hydrochlorothiazide alone may be switched to losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg (losartan 50 mg/hydrochlorothiazide 12.5 mg) once daily.
If blood pressure remains uncontrolled after about 3 weeks of therapy, the dose may be increased to two tablets of losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg once daily or one tablet of losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg (losartan 100 mg/hydrochlorothiazide 25 mg) once daily.
A patient whose blood pressure is not adequately controlled with losartan 100 mg monotherapy (see above) may be switched to losartan potassium and hydrochlorothiazide tablets USP, 100 mg/12.5 mg once daily.
If blood pressure remains uncontrolled after about 3 weeks of therapy, the dose may be increased to two tablets of losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg once daily or one tablet of losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg (losartan 100 mg/hydrochlorothiazide 25 mg) once daily.
A patient whose blood pressure is inadequately controlled by 25 mg once daily of hydrochlorothiazide, or is controlled but who experiences hypokalemia with this regimen, may be switched to losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg, (losartan 50 mg/hydrochlorothiazide 12.5 mg) once daily, reducing the dose of hydrochlorothiazide without reducing the overall expected antihypertensive response.
The clinical response to losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg should be subsequently evaluated, and if blood pressure remains uncontrolled after about 3 weeks of therapy, the dose may be increased to two tablets of losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg once daily or one tablet of losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg (losartan 100 mg/hydrochlorothiazide 25 mg) once daily.
The usual dose of losartan potassium and hydrochlorothiazide tablets USP is one tablet of losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg once daily.
More than two tablets of losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg once daily or more than one tablet of losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg once daily is not recommended.
The maximal antihypertensive effect is attained about 3 weeks after initiation of therapy.
Use in Patients With Renal Impairment The usual regimens of therapy with losartan potassium and hydrochlorothiazide tablets USP may be followed as long as the patient's creatinine clearance is greater than 30 mL/min.
In patients with more severe renal impairment, loop diuretics are preferred to thiazides, so losartan potassium and hydrochlorothiazide tablets USP are not recommended.
Patients With Hepatic Impairment Losartan potassium and hydrochlorothiazide tablets USP are not recommended for titration in patients with hepatic impairment (see WARNINGS , Impaired Hepatic Function ) because the appropriate 25 mg starting dose of losartan cannot be given.
Severe Hypertension The starting dose of losartan potassium and hydrochlorothiazide tablets USP for initial treatment of severe hypertension is one tablet of losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg once daily (see CLINICAL PHARMACOLOGY , Pharmacodynamics and Clinical Effects ).
For patients who do not respond adequately to losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg after 2 to 4 weeks of therapy, the dosage may be increased to one tablet of losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg once daily.
The maximum dose is one tablet of losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg once daily.
Losartan potassium and hydrochlorothiazide tablets USP are not recommended as initial therapy in patients with hepatic impairment (see WARNINGS , Impaired Hepatic Function ) because the appropriate 25 mg starting dose of losartan cannot be given.
It is also not recommended for use as initial therapy in patients with intravascular volume depletion (e.g., patients treated with diuretics, see WARNINGS , Hypotension —Volume–Depleted Patients ).
Hypertensive Patients With Left Ventricular Hypertrophy Treatment should be initiated with losartan potassium 50 mg once daily.
Hydrochlorothiazide 12.5 mg should be added or losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg substituted if the blood pressure reduction is inadequate.
If additional blood pressure reduction is needed, losartan potassium 100 mg and hydrochlorothiazide 12.5 mg or losartan potassium and hydrochlorothiazide tablets USP, 100 mg/12.5 mg may be substituted, followed by losartan potassium 100 mg and hydrochlorothiazide 25 mg or losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg.
For further blood pressure reduction other antihypertensives should be added (see CLINICAL PHARMACOLOGY , Pharmacodynamics and Clinical Effects , Losartan Potassium , Reduction in the risk of stroke ).
Losartan potassium and hydrochlorothiazide tablets USP may be administered with other antihypertensive agents.
Losartan potassium and hydrochlorothiazide tablets USP may be administered with or without food.

Quoted from the official label, section “Dosage & Administration”.

Other warnings

Fetal Toxicity Pregnancy Category D Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces renal function and increases fetal and neonatal morbidity and death.
Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations.
Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure, and death.
These adverse outcomes are usually associated with the use of these drugs in the second and third trimester of pregnancy.
Most epidemiologic studies examining fetal abnormalities after exposure to antihypertensive use in the first trimester have not distinguished drugs affecting the renin-angiotensin system from other antihypertensive agents.
Appropriate management of maternal hypertension during pregnancy is important to optimize outcomes for both mother and fetus.
In the unusual case that there is no appropriate alternative to therapy with drugs affecting the renin-angiotensin system for a particular patient, apprise the mother of the potential risk to the fetus.
Perform serial ultrasound examinations to assess the intra-amniotic environment.
If oligohydramnios is observed, discontinue losartan potassium and hydrochlorothiazide tablets, unless it is considered life-saving for the mother.
Fetal testing may be appropriate, based on the week of pregnancy.
Patients and physicians should be aware, however, that oligohydramnios may not appear until after the fetus has sustained irreversible injury.
Closely observe infants with histories of in utero exposure to losartan potassium and hydrochlorothiazide tablets for hypotension, oliguria, and hyperkalemia (see PRECAUTIONS , Pediatric Use ).
There was no evidence of teratogenicity in rats or rabbits treated with a maximum losartan potassium dose of 10 mg/kg/day in combination with 2.5 mg/kg/day of hydrochlorothiazide.
At these dosages, respective exposures (AUCs) of losartan, its active metabolite, and hydrochlorothiazide in rabbits were approximately 5, 1.5, and 1.0 times those achieved in humans with 100 mg losartan in combination with 25 mg hydrochlorothiazide.
AUC values for losartan, its active metabolite and hydrochlorothiazide, extrapolated from data obtained with losartan administered to rats at a dose of 50 mg/kg/day in combination with 12.5 mg/kg/day of hydrochlorothiazide, were approximately 6, 2, and 2 times greater than those achieved in humans with 100 mg of losartan in combination with 25 mg of hydrochlorothiazide.
Fetal toxicity in rats, as evidenced by a slight increase in supernumerary ribs, was observed when females were treated prior to and throughout gestation with 10 mg/kg/day losartan in combination with 2.5 mg/kg/day hydrochlorothiazide.
As also observed in studies with losartan alone, adverse fetal and neonatal effects, including decreased body weight, renal toxicity, and mortality, occurred when pregnant rats were treated during late gestation and/or lactation with 50 mg/kg/day losartan in combination with 12.5 mg/kg/day hydrochlorothiazide.
Respective AUCs for losartan, its active metabolite and hydrochlorothiazide at these dosages in rats were approximately 35, 10 and 10 times greater than those achieved in humans with the administration of 100 mg of losartan in combination with 25 mg hydrochlorothiazide.
When hydrochlorothiazide was administered without losartan to pregnant mice and rats during their respective periods of major organogenesis, at doses up to 3000 and 1000 mg/kg/day, respectively, there was no evidence of harm to the fetus.
Thiazides cross the placental barrier and appear in cord blood.
There is a risk of fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in
adults.
Hypotension — Volume-Depleted Patients In patients who are intravascularly volume-depleted (e.g., those treated with diuretics), symptomatic hypotension may occur after initiation of therapy with losartan potassium and hydrochlorothiazide tablets.
This condition should be corrected prior to administration of losartan potassium and hydrochlorothiazide tablets (see DOSAGE AND ADMINISTRATION ).
Impaired Hepatic Function Losartan Potassium and Hydrochlorothiazide Losartan potassium and hydrochlorothiazide tablets are not recommended for patients with hepatic impairment who require titration with losartan.
Hydrochlorothiazide Thiazides should be used with caution in patients with impaired hepatic function or progressive liver disease, since minor alterations of fluid and electrolyte balance may precipitate hepatic coma.
Hypersensitivity Reaction Hypersensitivity reactions to hydrochlorothiazide may occur in patients with or without a history of allergy or bronchial asthma, but are more likely in patients with such a history.
Systemic Lupus Erythematosus Thiazide diuretics have been reported to cause exacerbation or activation of systemic lupus erythematosus.
Lithium Interaction Lithium generally should not be given with thiazides.
Monitor serum lithium levels in patients receiving lithium and hydrochlorothiazide (see PRECAUTIONS , Drug Interactions , Hydrochlorothiazid e , Lithium ) .
Acute Myopia and Secondary Angle-Closure Glaucoma Hydrochlorothiazide, a sulfonamide, can cause an idiosyncratic reaction, resulting in acute transient myopia and acute angle-closure glaucoma.
Symptoms include acute onset of decreased visual acuity or ocular pain and typically occur within hours to weeks of drug initiation.
Untreated acute angle-closure glaucoma can lead to permanent vision loss.
The primary treatment is to discontinue hydrochlorothiazide as rapidly as possible.
Prompt medical or surgical treatments may need to be considered if the intraocular pressure remains uncontrolled.
Risk factors for developing acute angle-closure glaucoma may include a history of sulfonamide or penicillin allergy.
General Hypersensitivity Angioedema.
See ADVERSE REACTIONS , Postmarketing Experience .
Losartan Potassium and Hydrochlorothiazide In double-blind clinical trials of various doses of losartan potassium and hydrochlorothiazide, the incidence of hypertensive patients who developed hypokalemia (serum potassium < 3.5 mEq/L) was 6.7% versus 3.5% for placebo; the incidence of hyperkalemia (serum potassium > 5.7 mEq/L) was 0.4%.
No patient discontinued due to increases or decreases in serum potassium.
The mean decrease in serum potassium in patients treated with various doses of losartan and hydrochlorothiazide was 0.123 mEq/L.
In patients treated with various doses of losartan and hydrochlorothiazide, there was also a dose-related decrease in the hypokalemic response to hydrochlorothiazide as the dose of losartan was increased, as well as a dose-related decrease in serum uric acid with increasing doses of losartan.
Hydrochlorothiazide Periodic determination of serum electrolytes to detect possible electrolyte imbalance should be performed at appropriate intervals.
All patients receiving thiazide therapy should be observed for clinical signs of fluid or electrolyte imbalance:
hyponatremia, hypochloremic alkalosis, and hypokalemia.
Serum and urine electrolyte determinations are particularly important when the patient is vomiting excessively or receiving parenteral fluids.
Warning signs or symptoms of fluid and electrolyte imbalance, irrespective of cause, include dryness of mouth, thirst, weakness, lethargy, drowsiness, restlessness, confusion, seizures, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, and gastrointestinal disturbances such as nausea and vomiting.
Hypokalemia may develop, especially with brisk diuresis, when severe cirrhosis is present, or after prolonged therapy.
Interference with adequate oral electrolyte intake will also contribute to hypokalemia.
Hypokalemia may cause cardiac arrhythmia and may also sensitize or exaggerate the response of the heart to the toxic effects of digitalis (e.g., increased ventricular irritability).
Although any chloride deficit is generally mild and usually does not require specific treatment except under extraordinary circumstances (as in liver disease or renal disease), chloride replacement may be required in the treatment of metabolic alkalosis.
Dilutional hyponatremia may occur in edematous patients in hot weather; appropriate therapy is water restriction, rather than administration of salt except in rare instances when the hyponatremia is life-threatening.
In actual salt depletion, appropriate replacement is the therapy of choice.
Hyperuricemia may occur or frank gout may be precipitated in certain patients receiving thiazide therapy.
Because losartan decreases uric acid, losartan in combination with hydrochlorothiazide attenuates the diuretic-induced hyperuricemia.
In diabetic patients, dosage adjustments of insulin or oral hypoglycemic agents may be required.
Hyperglycemia may occur with thiazide diuretics.
Thus latent diabetes mellitus may become manifest during thiazide therapy.
The antihypertensive effects of the drug may be enhanced in the postsympathectomy patient.
If progressive renal impairment becomes evident, consider withholding or discontinuing diuretic therapy.
Thiazides have been shown to increase the urinary excretion of magnesium; this may result in hypomagnesemia.
Thiazides may decrease urinary calcium excretion.
Thiazides may cause intermittent and slight elevation of serum calcium in the absence of known disorders of calcium metabolism.
Marked hypercalcemia may be evidence of hidden hyperparathyroidism.
Thiazides should be discontinued before carrying out tests for parathyroid function.
Increases in cholesterol and triglyceride levels may be associated with thiazide diuretic therapy.
Impaired Renal Function As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function have been reported in susceptible individuals treated with losartan; in some patients, these changes in renal function were reversible upon discontinuation of therapy.
In patients whose renal function may depend on the activity of the renin-angiotensin-aldosterone system (e.g., patients with severe congestive heart failure), treatment with angiotensin converting enzyme inhibitors has been associated with oliguria and/or progressive azotemia and (rarely) with acute renal failure and/or death.
Similar outcomes have been reported with losartan.
In studies of ACE inhibitors in patients with unilateral or bilateral renal artery stenosis, increases in serum creatinine or BUN have been reported.
Similar effects have been reported with losartan; in some patients, these effects were reversible upon discontinuation of therapy.
Thiazides should be used with caution in severe renal disease.
In patients with renal disease, thiazides may precipitate azotemia.
Cumulative effects of the drug may develop in patients with impaired renal function.
Information for Patients Pregnancy Female patients of childbearing age should be told about the consequences of exposure to losartan potassium and hydrochlorothiazide tablets during pregnancy.
Drug Interactions Losartan Potassium No significant drug-drug pharmacokinetic interactions have been found in interaction studies with hydrochlorothiazide, digoxin, warfarin, cimetidine and phenobarbital.
Carcinogenesis, Mutagenesis, Impairment of Fertility Losartan Potassium and Hydrochlorothiazide No carcinogenicity studies have been conducted with the losartan potassium and hydrochlorothiazide combination.
Losartan potassium and hydrochlorothiazide when tested at a weight ratio of 4:1 was negative in the Ames microbial mutagenesis assay and the V-79 Chinese hamster lung cell mutagenesis assay.
In addition, there was no evidence of direct genotoxicity in the in vitro alkaline elution assay in rat hepatocytes and in vitro chromosomal aberration assay in Chinese hamster ovary cells at noncytotoxic concentrations.
Losartan potassium, coadministered with hydrochlorothiazide, had no effect on the fertility or mating behavior of male rats at dosages up to 135 mg/kg/day of losartan and 33.75 mg/kg/day of hydrochlorothiazide.
These dosages have been shown to provide respective systemic exposures (AUCs) for losartan, its active metabolite and hydrochlorothiazide that are approximately 60, 60 and 30 times greater than those achieved in humans with 100 mg of losartan potassium in combination with 25 mg of hydrochlorothiazide.
In female rats, however, the coadministration of doses as low as 10 mg/kg/day of losartan and 2.5 mg/kg/day of hydrochlorothiazide was associated with slight but statistically significant decreases in fecundity and fertility indices.
AUC values for losartan, its active metabolite and hydrochlorothiazide, extrapolated from data obtained with losartan administered to rats at a dose of 50 mg/kg/day in combination with 12.5 mg/kg/day of hydrochlorothiazide, were approximately 6, 2, and 2 times greater than those achieved in humans with 100 mg of losartan in combination with 25 mg of hydrochlorothiazide.
Losartan Potassium Losartan potassium was not carcinogenic when administered at maximally tolerated dosages to rats and mice for 105 and 92 weeks, respectively.
Female rats given the highest dose (270 mg/kg/day) had a slightly higher incidence of pancreatic acinar adenoma.
The maximally tolerated dosages (270 mg/kg/day in rats, 200 mg/kg/day in mice) provided systemic exposures for losartan and its pharmacologically active metabolite that were approximately 160 and 90 times (rats) and 30 and 15 times (mice) the exposure of a 50 kg human given 100 mg per day.
Losartan potassium was negative in the microbial mutagenesis and V-79 mammalian cell mutagenesis assays and in the in vitro alkaline elution and in vitro and in vivo chromosomal aberration assays.
In addition, the active metabolite showed no evidence of genotoxicity in the microbial mutagenesis, in vitro alkaline elution, and in vitro chromosomal aberration assays.
Fertility and reproductive performance were not affected in studies with male rats given oral doses of losartan potassium up to approximately 150 mg/kg/day.
The administration of toxic dosage levels in females (300/200 mg/kg/day) was associated with a significant (p < 0.05) decrease in the number of corpora lutea/female, implants/female, and live fetuses/female at C-section.
At 100 mg/kg/day only a decrease in the number of corpora lutea/female was observed.
The relationship of these findings to drug-treatment is uncertain since there was no effect at these dosage levels on implants/pregnant female, percent post-implantation loss, or live animals/litter at parturition.
In nonpregnant rats dosed at 135 mg/kg/day for 7 days, systemic exposure (AUCs) for losartan and its active metabolite were approximately 66 and 26 times the exposure achieved in man at the maximum recommended human daily dosage (100 mg).
Hydrochlorothiazide Two-year feeding studies in mice and rats conducted under the auspices of the National Toxicology Program (NTP) uncovered no evidence of a carcinogenic potential of hydrochlorothiazide in female mice (at doses of up to approximately 600 mg/kg/day) or in male and female rats (at doses of up to approximately 100 mg/kg/day).
The NTP, however, found equivocal evidence for hepatocarcinogenicity in male mice.
Hydrochlorothiazide was not genotoxic in vitro in the Ames mutagenicity assay of Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537, and TA 1538 and in the Chinese Hamster Ovary (CHO) test for chromosomal aberrations, or in vivo in assays using mouse germinal cell chromosomes, Chinese hamster bone marrow chromosomes, and the Drosophila sex-linked recessive lethal trait gene.
Positive test results were obtained only in the in vitro CHO Sister Chromatid Exchange (clastogenicity) and in the Mouse Lymphoma Cell (mutagenicity) assays, using concentrations of hydrochlorothiazide from 43 to 1300 mcg/mL, and in the Aspergillus nidulans non-disjunction assay at an unspecified concentration.
Hydrochlorothiazide had no adverse effects on the fertility of mice and rats of either sex in studies wherein these species were exposed, via their diet, to doses of up to 100 and 4 mg/kg, respectively, prior to mating and throughout gestation.
Nursing Mothers It is not known whether losartan is excreted in human milk, but significant levels of losartan and its active metabolite were shown to be present in rat milk.
Pediatric Use Safety and effectiveness of losartan potassium and hydrochlorothiazide tablets in pediatric patients have not been established.
Geriatric Use In a controlled clinical study for the reduction in the combined risk of cardiovascular death, stroke and myocardial infarction in hypertensive patients with left ventricular hypertrophy, 2857 patients (62%) were 65 years and over, while 808 patients (18%) were 75 years and over.
Race In the LIFE study, Black patients with hypertension and left ventricular hypertrophy had a lower risk of stroke on atenolol than on losartan (both cotreated with hydrochlorothiazide in the majority of patients).
Given the difficulty in interpreting subset differences in large trials, it cannot be known whether the observed difference is the result of chance.
However, the LIFE study does not provide evidence that the benefits of losartan on reducing the risk of cardiovascular events in hypertensive patients with left ventricular hypertrophy apply to Black patients (see CLINICAL PHARMACOLOGY , Pharmacodynamics and Clinical Effects ;
General Hypersensitivity Angioedema.
See ADVERSE REACTIONS , Postmarketing Experience .
Losartan Potassium and Hydrochlorothiazide In double-blind clinical trials of various doses of losartan potassium and hydrochlorothiazide, the incidence of hypertensive patients who developed hypokalemia (serum potassium < 3.5 mEq/L) was 6.7% versus 3.5% for placebo; the incidence of hyperkalemia (serum potassium > 5.7 mEq/L) was 0.4%.
No patient discontinued due to increases or decreases in serum potassium.
The mean decrease in serum potassium in patients treated with various doses of losartan and hydrochlorothiazide was 0.123 mEq/L.
In patients treated with various doses of losartan and hydrochlorothiazide, there was also a dose-related decrease in the hypokalemic response to hydrochlorothiazide as the dose of losartan was increased, as well as a dose-related decrease in serum uric acid with increasing doses of losartan.
Hydrochlorothiazide Periodic determination of serum electrolytes to detect possible electrolyte imbalance should be performed at appropriate intervals.
All patients receiving thiazide therapy should be observed for clinical signs of fluid or electrolyte imbalance:
hyponatremia, hypochloremic alkalosis, and hypokalemia.
Serum and urine electrolyte determinations are particularly important when the patient is vomiting excessively or receiving parenteral fluids.
Warning signs or symptoms of fluid and electrolyte imbalance, irrespective of cause, include dryness of mouth, thirst, weakness, lethargy, drowsiness, restlessness, confusion, seizures, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, and gastrointestinal disturbances such as nausea and vomiting.
Hypokalemia may develop, especially with brisk diuresis, when severe cirrhosis is present, or after prolonged therapy.
Interference with adequate oral electrolyte intake will also contribute to hypokalemia.
Hypokalemia may cause cardiac arrhythmia and may also sensitize or exaggerate the response of the heart to the toxic effects of digitalis (e.g., increased ventricular irritability).
Although any chloride deficit is generally mild and usually does not require specific treatment except under extraordinary circumstances (as in liver disease or renal disease), chloride replacement may be required in the treatment of metabolic alkalosis.
Dilutional hyponatremia may occur in edematous patients in hot weather; appropriate therapy is water restriction, rather than administration of salt except in rare instances when the hyponatremia is life-threatening.
In actual salt depletion, appropriate replacement is the therapy of choice.
Hyperuricemia may occur or frank gout may be precipitated in certain patients receiving thiazide therapy.
Because losartan decreases uric acid, losartan in combination with hydrochlorothiazide attenuates the diuretic-induced hyperuricemia.
In diabetic patients, dosage adjustments of insulin or oral hypoglycemic agents may be required.
Hyperglycemia may occur with thiazide diuretics.
Thus latent diabetes mellitus may become manifest during thiazide therapy.
The antihypertensive effects of the drug may be enhanced in the postsympathectomy patient.
If progressive renal impairment becomes evident, consider withholding or discontinuing diuretic therapy.
Thiazides have been shown to increase the urinary excretion of magnesium; this may result in hypomagnesemia.
Thiazides may decrease urinary calcium excretion.
Thiazides may cause intermittent and slight elevation of serum calcium in the absence of known disorders of calcium metabolism.
Marked hypercalcemia may be evidence of hidden hyperparathyroidism.
Thiazides should be discontinued before carrying out tests for parathyroid function.
Increases in cholesterol and triglyceride levels may be associated with thiazide diuretic therapy.

Quoted from the official label, section “Warnings”.

Pregnancy and breastfeeding

It is not known whether losartan is excreted in human milk, but significant levels of losartan and its active metabolite were shown to be present in rat milk.
Thiazides appear in human milk.
Because of the potential for adverse effects on the nursing infant, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
Special Populations Pediatric Losartan pharmacokinetics have been investigated in patients 6 to 16 years (see PRECAUTIONS , Pediatric Use ) .
Geriatric and gender Losartan pharmacokinetics have been investigated in the elderly (65 to 75 years) and in both genders.
Plasma concentrations of losartan and its active metabolite are similar in elderly and young hypertensives.
Plasma concentrations of losartan were about twice as high in female hypertensives as male hypertensives, but concentrations of the active metabolite were similar in males and females.
Race Pharmacokinetic differences due to race have not been studied (see also PRECAUTIONS , Race and CLINICAL PHARMACOLOGY , Pharmacodynamics and Clinical Effects , LosartanPotassium , Reduction in the risk of stroke , Race ).
Renal insufficiency Losartan Following oral administration, plasma concentrations and AUCs of losartan and its active metabolite are increased by 50 to 90% in patients with mild (creatinine clearance of 50 to 74 mL/min) or moderate (creatinine clearance 30 to 49 mL/min) renal insufficiency.
In this study, renal clearance was reduced by 55 to 85% for both losartan and its active metabolite in patients with mild or moderate renal insufficiency.
Neither losartan nor its active metabolite can be removed by hemodialysis.
Hydrochlorothiazide Following oral administration, the AUC for hydrochlorothiazide is increased by 70 and 700% for patients with mild and moderate renal insufficiency, respectively.
In this study, renal clearance of hydrochlorothiazide decreased by 45 and 85% in patients with mild and moderate renal impairment, respectively.
The usual regimens of therapy with losartan potassium and hydrochlorothiazide tablets may be followed as long as the patient's creatinine clearance is > 30 mL/min.
In patients with more severe renal impairment, loop diuretics are preferred to thiazides, so losartan potassium and hydrochlorothiazide tablets are not recommended (see DOSAGE AND ADMINISTRATION ).
Hepatic insufficiency Following oral administration in patients with mild to moderate alcoholic cirrhosis of the liver, plasma concentrations of losartan and its active metabolite were, respectively, 5 times and about 1.7 times those in young male volunteers.
Compared to normal subjects, the total plasma clearance of losartan in patients with hepatic insufficiency was about 50% lower, and the oral bioavailability was about 2 times higher.
The lower starting dose of losartan recommended for use in patients with hepatic impairment cannot be given using losartan potassium and hydrochlorothiazide tablets.
Its use in such patients as a means of losartan titration is, therefore, not recommended (see DOSAGE AND ADMINISTRATION ).

Quoted from the official label, section “OTC — Pregnancy or Breast Feeding”.

Other medicines

Losartan potassium Losartan, administered for 12 days, did not affect the pharmacokinetics or pharmacodynamics of a single dose of warfarin.
Losartan did not affect the pharmacokinetics of oral or intravenous digoxin.
There is no pharmacokinetic interaction between losartan and hydrochlorothiazide.
Coadministration of losartan and cimetidine led to an increase of about 18% in AUC of losartan but did not affect the pharmacokinetics of its active metabolite.
Coadministration of losartan and phenobarbital led to a reduction of about 20% in the AUC of losartan and that of its active metabolite.
A somewhat greater interaction (approximately 40% reduction in the AUC of active metabolite and approximately 30% reduction in the AUC of losartan) has been reported with rifampin.
Fluconazole, an inhibitor of cytochrome P450 2C9, decreased the AUC of the active metabolite by approximately 40%, but increased the AUC of losartan by approximately 70% following multiple doses.
Conversion of losartan to its active metabolite after intravenous administration is not affected by ketoconazole, an inhibitor of P450 3A4.
The AUC of active metabolite following oral losartan was not affected by erythromycin, another inhibitor of P450 3A4, but the AUC of losartan was increased by 30%.
Hydrochlorothiazide After oral administration of hydrochlorothiazide, diuresis begins within 2 hours, peaks in about 4 hours and lasts about 6 to 12 hours.
Hydrochlorothiazide is not metabolized but is eliminated rapidly by the kidney.
When plasma levels have been followed for at least 24 hours, the plasma half-life has been observed to vary between 5.6 and 14.8 hours.
At least 61 percent of the oral dose is eliminated unchanged within 24 hours.
Hydrochlorothiazide crosses the placental but not the blood-brain barrier and is excreted in breast milk.
Losartan Potassium No significant drug-drug pharmacokinetic interactions have been found in interaction studies with hydrochlorothiazide, digoxin, warfarin, cimetidine and phenobarbital.
Rifampin, an inducer of drug metabolism, decreased the concentrations of losartan and its active metabolite (see CLINICAL PHARMACOLOGY , Drug Interactions ).
In humans, two inhibitors of P450 3A4 have been studied.
Ketoconazole did not affect the conversion of losartan to the active metabolite after intravenous administration of losartan, and erythromycin had no clinically significant effect after oral administration.
Fluconazole, an inhibitor of P450 2C9, decreased active metabolite concentration and increased losartan concentration.
The pharmacodynamic consequences of concomitant use of losartan and inhibitors of P450 2C9 have not been examined.
Subjects who do not metabolize losartan to active metabolite have been shown to have a specific, rare defect in cytochrome P450 2C9.
These data suggest that the conversion of losartan to its active metabolite is mediated primarily by P450 2C9 and not P450 3A4.
As with other drugs that block angiotensin II or its effects, concomitant use of potassium-sparing diuretics (e.g., spironolactone, triamterene, amiloride), potassium supplements, or salt substitutes containing potassium may lead to increases in serum potassium (see PRECAUTIONS , Information for Patients, Potassium Supplements ).
Lithium Increases in serum lithium concentrations and lithium toxicity have been reported during concomitant administration of lithium with angiotensin II receptor antagonists.
Monitor serum lithium levels during concomitant use.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, coadministration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists (including losartan) may result in deterioration of renal function, including possible acute renal failure.
These effects are usually reversible.
Monitor renal function periodically in patients receiving losartan and NSAID therapy.
The antihypertensive effect of angiotensin II receptor antagonists, including losartan, may be attenuated by NSAIDs, including selective COX-2 inhibitors.
Dual Blockade of the Renin-Angiotensin System (RAS) Dual blockade of the RAS with angiotensin receptor blockers, ACE inhibitors, or aliskiren is associated with increased risks of hypotension, syncope, hyperkalemia, and changes in renal function (including acute renal failure) compared to monotherapy.
The Veterans Affairs Nephropathy in Diabetes (VA NEPHRON-D) trial enrolled 1448 patients with type 2 diabetes, elevated urinary-albumin-to-creatinine ratio, and decreased estimated glomerular filtration rate (GFR 30 to 89.9 ml/min), randomized them to lisinopril or placebo on a background of losartan therapy and followed them for a median of 2.2 years.
Patients receiving the combination of losartan and lisinopril did not obtain any additional benefit compared to monotherapy for the combined endpoint of decline in GFR, end stage renal disease, or death, but experienced an increased incidence of hyperkalemia and acute kidney injury compared with the monotherapy group.
Closely monitor blood pressure, renal function, and electrolytes in patients on losartan potassium and hydrochlorothiazide tablets and other agents that affect the RAS.
Do not coadminister aliskiren with losartan potassium and hydrochlorothiazide tablets in patients with diabetes.
Avoid use of aliskiren with losartan potassium and hydrochlorothiazide tablets in patients with renal impairment (GFR < 60 ml/min).
Hydrochlorothiazide When administered concurrently, the following drugs may interact with thiazide diuretics:
Alcohol, barbiturates, or narcotics — potentiation of orthostatic hypotension may occur.
Antidiabetic drugs (oral agents and insulin) — dosage adjustment of the antidiabetic drug may be required.
Other antihypertensive drugs — additive effect or potentiation.
Cholestyramine and colestipol resins — Absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins.
Single doses of either cholestyramine or colestipol resins bind the hydrochlorothiazide and reduce its absorption from the gastrointestinal tract by up to 85 and 43 percent, respectively.
Corticosteroids, ACTH, or glycyrrhizin (found in liquorice) — intensified electrolyte depletion, particularly hypokalemia.
Pressor amines (e.g., norepinephrine) — possible decreased response to pressor amines but not sufficient to preclude their use.
Skeletal muscle relaxants, nondepolarizing (e.g., tubocurarine) — possible increased responsiveness to the muscle relaxant.
Lithium — should not generally be given with diuretics.
Diuretic agents reduce the renal clearance of lithium and add a high risk of lithium toxicity.
Monitor serum lithium levels during concomitant use.Refer to the package insert for lithium preparations before use of such preparations with losartan potassium and hydrochlorothiazide tablets.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) — The administration of a non-steroidal anti-inflammatory agent, including a selective cyclooxygenase-2 inhibitor, can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics.
Therefore, when losartan potassium and hydrochlorothiazide tablets and non-steroidal anti-inflammatory agents, including selective cyclooxygenase-2 inhibitors, are used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is obtained.
In patients receiving diuretic therapy, coadministration of NSAIDs with angiotensin receptor blockers, including losartan, may result in deterioration of renal function, including possible acute renal failure.
These effects are usually reversible.
Monitor renal function periodically in patients receiving hydrochlorothiazide, losartan, and NSAID therapy.

Quoted from the official label, section “Drug Interactions”.

If you take too much

In an emergency, call your local emergency number or a poison control centre.

Losartan Potassium Significant lethality was observed in mice and rats after oral administration of 1000 mg/kg and 2000 mg/kg, respectively, about 44 and 170 times the maximum recommended human dose on a mg/m 2 basis.
Limited data are available in regard to overdosage in humans.
The most likely manifestation of overdosage would be hypotension and tachycardia; bradycardia could occur from parasympathetic (vagal) stimulation.
If symptomatic hypotension should occur, supportive treatment should be instituted.
Neither losartan nor its active metabolite can be removed by hemodialysis.
Hydrochlorothiazide The oral LD 50 of hydrochlorothiazide is greater than 10 g/kg in both mice and rats.
The most common signs and symptoms observed are those caused by electrolyte depletion (hypokalemia, hypochloremia, hyponatremia) and dehydration resulting from excessive diuresis.
If digitalis has also been administered, hypokalemia may accentuate cardiac arrhythmias.
The degree to which hydrochlorothiazide is removed by hemodialysis has not been established.

Quoted from the official label, section “Overdosage”.

Use in children

Safety and effectiveness of losartan potassium and hydrochlorothiazide tablets in pediatric patients have not been established.
Neonates with a history of in utero exposure to losartan potassium and hydrochlorothiazide tablets:
If oliguria or hypotension occurs, direct attention toward support of blood pressure and renal perfusion.
Exchange transfusions or dialysis may be required as a means of reversing hypotension and/or substituting for disordered renal function.

Quoted from the official label, section “Pediatric Use”.

Use in older people

In a controlled clinical study for the reduction in the combined risk of cardiovascular death, stroke and myocardial infarction in hypertensive patients with left ventricular hypertrophy, 2857 patients (62%) were 65 years and over, while 808 patients (18%) were 75 years and over.
In an effort to control blood pressure in this study, patients were coadministered losartan and hydrochlorothiazide 74% of the total time they were on study drug.
No overall differences in effectiveness were observed between these patients and younger patients.
Adverse events were somewhat more frequent in the elderly compared to non-elderly patients for both the losartan and hydrochlorothiazide and the control groups (see CLINICAL PHARMACOLOGY , Special Populations ).

Quoted from the official label, section “Geriatric Use”.

Side effects

Losartan potassium and hydrochlorothiazide has been evaluated for safety in 858 patients treated for essential hypertension and 3889 patients treated for hypertension and left ventricular hypertrophy.
In clinical trials with losartan potassium and hydrochlorothiazide, no adverse experiences peculiar to this combination have been observed.
Adverse experiences have been limited to those that were reported previously with losartan potassium and/or hydrochlorothiazide.
The overall incidence of adverse experiences reported with the combination was comparable to placebo.
In general, treatment with losartan potassium and hydrochlorothiazide was well tolerated.
For the most part, adverse experiences have been mild and transient in nature and have not required discontinuation of therapy.
In controlled clinical trials, discontinuation of therapy due to clinical adverse experiences was required in only 2.8% and 2.3% of patients treated with the combination and placebo, respectively.
In these double-blind controlled clinical trials, the following adverse experiences reported with losartan and hydrochlorothiazide occurred in ≥ 1 percent of patients, and more often on drug than placebo, regardless of drug relationship:
Table 1:
Losartan Potassium and Hydrochlorothiazide (n = 858) Placebo (n = 173) Body as a Whole Abdominal pain 1.2
0.6 Edema/swelling 1.3
1.2 Cardiovascular Palpitation 1.4
0.0 Musculoskeletal Back pain 2.1
0.6 Nervous/Psychiatric Dizziness 5.7
2.9 Respiratory Cough 2.6
2.3 Sinusitis 1.2
0.6 Upper respiratory infection 6.1
4.6 Skin Rash 1.4
0.0 The following adverse events were also reported at a rate of 1% or greater, but were as, or more, common in the placebo group in studies of essential hypertension:
asthenia/fatigue, diarrhea, nausea, headache, bronchitis, pharyngitis.
Adverse events occurred at about the same rates in men and women.
Adverse events were somewhat more frequent in the elderly compared to non-elderly patients and somewhat more frequent in Blacks compared to non-Blacks for both the losartan and hydrochlorothiazide and the control groups.
A patient with known hypersensitivity to aspirin and penicillin, when treated with losartan potassium, was withdrawn from study due to swelling of the lips and eyelids and facial rash, reported as angioedema, which returned to normal 5 days after therapy was discontinued.
Superficial peeling of palms and hemolysis were reported in one subject treated with losartan potassium.
Losartan Potassium Other adverse experiences that have been reported with losartan, without regard to causality, are listed below:
Body as a Whole:
chest pain, facial edema, fever, orthostatic effects, syncope;
Cardiovascular:
angina pectoris, arrhythmias including atrial fibrillation, sinus bradycardia, tachycardia, ventricular tachycardia and ventricular fibrillation, CVA, hypotension, myocardial infarction, second degree AV block;
Digestive:
anorexia, constipation, dental pain, dry mouth, dyspepsia, flatulence, gastritis, vomiting;
General disorders and administration site conditions: malaise;
Hematologic: anemia;
Metabolic: gout;
Musculoskeletal:
arm pain, arthralgia, arthritis, fibromyalgia, hip pain, joint swelling, knee pain, leg pain, muscle cramps, muscle weakness, musculoskeletal pain, myalgia, shoulder pain, stiffness;
Nervous System/Psychiatric:
anxiety, anxiety disorder, ataxia, confusion, depression, dream abnormality, hypesthesia, insomnia, libido decreased, memory impairment, migraine, nervousness, panic disorder, paresthesia, peripheral neuropathy, sleep disorder, somnolence, tremor, vertigo;
Respiratory:
dyspnea, epistaxis, nasal congestion, pharyngeal discomfort, respiratory congestion, rhinitis, sinus disorder;
Skin:
alopecia, dermatitis, dry skin, ecchymosis, erythema, flushing, photosensitivity, pruritus, sweating, urticaria;
Special Senses:
blurred vision, burning/stinging in the eye, conjunctivitis, decrease in visual acuity, taste perversion, tinnitus;
Urogenital: impotence, nocturia, urinary frequency, urinary tract infection.
Hydrochlorothiazide Other adverse experiences that have been reported with hydrochlorothiazide, without regard to causality, are listed below:
Body as a Whole:
weakness;
Digestive:
pancreatitis, jaundice (intrahepatic cholestatic jaundice), sialadenitis, cramping, gastric irritation;
Hematologic:
aplastic anemia, agranulocytosis, leukopenia, hemolytic anemia, thrombocytopenia;
Hypersensitivity:
purpura, photosensitivity, urticaria, necrotizing angiitis (vasculitis and cutaneous vasculitis), fever, respiratory distress including pneumonitis and pulmonary edema;
Metabolic: hyperglycemia, glycosuria, hyperuricemia;
Musculoskeletal: muscle spasm;
Nervous System/Psychiatric: restlessness;
Renal: renal failure, renal dysfunction, interstitial nephritis;
Skin:
erythema multiforme including Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal necrolysis;
Special Senses: transient blurred vision, xanthopsia.
Persistent dry cough (with an incidence of a few percent) has been associated with ACE-inhibitor use and in practice can be a cause of discontinuation of ACE-inhibitor therapy.
Two prospective, parallel-group, double-blind, randomized, controlled trials were conducted to assess the effects of losartan on the incidence of cough in hypertensive patients who had experienced cough while receiving ACE-inhibitor therapy.
Patients who had typical ACE-inhibitor cough when challenged with lisinopril, whose cough disappeared on placebo, were randomized to losartan 50 mg, lisinopril 20 mg, or either placebo (one study, n = 97) or 25 mg hydrochlorothiazide (n = 135).
The double-blind treatment period lasted up to 8 weeks.
The incidence of cough is shown below.
Table 2:
Study 1 HCTZ Losartan Lisinopril Cough 25% 17% 69% Study 2 Placebo Losartan Lisinopril Cough 35% 29% 62% These studies demonstrate that the incidence of cough associated with losartan therapy, in a population that all had cough associated with ACE-inhibitor therapy, is similar to that associated with hydrochlorothiazide or placebo therapy.
Cases of cough, including positive re-challenges, have been reported with the use of losartan in postmarketing experience.
Severe Hypertension In a clinical study in patients with severe hypertension (SiDBP ≥ 110 mmHg), the overall pattern of adverse events reported through six weeks of follow-up was similar in patients treated with losartan potassium and hydrochlorothiazide tablets as initial therapy and in patients treated with losartan as initial therapy.
There were no reported cases of syncope in either treatment group.
There were 2 (0.6%) and 0 (0.0%) cases of hypotension reported in the group treated with losartan potassium and hydrochlorothiazide tablets and the group treated with losartan, respectively.
There were 3 (0.8%) and 2 (1.2%) cases of increased serum creatinine (> 0.5 mg/dL) in the group treated with losartan potassium and hydrochlorothiazide tablets and the group treated with losartan, respectively, during the same time period (see CLINICAL PHARMACOLOGY , Pharmacodynamics and Clinical Effects , Severe Hypertension ).
Postmarketing Experience The following additional adverse reactions have been reported in postmarketing experience:
Digestive Hepatitis has been reported rarely in patients treated with losartan.
Hemic Thrombocytopenia.
Hypersensitivity Angioedema, including swelling of the larynx and glottis, causing airway obstruction and/or swelling of the face, lips, pharynx, and/or tongue has been reported rarely in patients treated with losartan; some of these patients previously experienced angioedema with other drugs including ACE inhibitors.
Vasculitis, including Henoch-Schönlein purpura, has been reported with losartan.
Anaphylactic reactions have been reported.
Metabolic and nutrition Hyperkalemia, hyponatremia have been reported with losartan.
Musculoskeletal Rare cases of rhabdomyolysis have been reported in patients receiving angiotensin II receptor blockers.
Respiratory Dry cough (see above) has been reported with losartan.
Skin Erythroderma has been reported with losartan.
Laboratory Test Findings In controlled clinical trials, clinically important changes in standard laboratory parameters were rarely associated with administration of losartan potassium and hydrochlorothiazide tablets.
Creatinine, blood urea nitrogen Minor increases in blood urea nitrogen (BUN) or serum creatinine were observed in 0.6 and 0.8 percent, respectively, of patients with essential hypertension treated with losartan potassium and hydrochlorothiazide tablets alone.
No patient discontinued taking losartan potassium and hydrochlorothiazide tablets due to increased BUN.
One patient discontinued taking losartan potassium and hydrochlorothiazide tablets due to a minor increase in serum creatinine.
Hemoglobin and hematocrit Small decreases in hemoglobin and hematocrit (mean decreases of approximately 0.14 grams percent and 0.72 volume percent, respectively) occurred frequently in patients treated with losartan potassium and hydrochlorothiazide tablets alone, but were rarely of clinical importance.
No patients were discontinued due to anemia.
Liver function tests Occasional elevations of liver enzymes and/or serum bilirubin have occurred.
In patients with essential hypertension treated with losartan potassium and hydrochlorothiazide tablets alone, no patients were discontinued due to these laboratory adverse experiences.
Serum electrolytes See PRECAUTIONS .

Quoted from the official label, section “Adverse Reactions”.

What to discuss with your doctor

Pregnancy Female patients of childbearing age should be told about the consequences of exposure to losartan potassium and hydrochlorothiazide tablets during pregnancy.
Discuss treatment options with women planning to become pregnant.
Patients should be asked to report pregnancies to their physicians as soon as possible.
Symptomatic Hypotension A patient receiving losartan potassium and hydrochlorothiazide tablets should be cautioned that lightheadedness can occur, especially during the first days of therapy, and that it should be reported to the prescribing physician.
The patients should be told that if syncope occurs, losartan potassium and hydrochlorothiazide tablets should be discontinued until the physician has been consulted.
All patients should be cautioned that inadequate fluid intake, excessive perspiration, diarrhea, or vomiting can lead to an excessive fall in blood pressure, with the same consequences of lightheadedness and possible syncope.
Potassium Supplements A patient receiving losartan potassium and hydrochlorothiazide tablets should be told not to use potassium supplements or salt substitutes containing potassium without consulting the prescribing physician (see PRECAUTIONS , Drug Interactions , Losartan Potassium ).

Quoted from the official label, section “Patient Counseling Information”.

What it looks like and how it is packed

Losartan potassium and hydrochlorothiazide tablets USP are available as:
100 mg/25 mg are light yellow, film-coated, oval-shaped tablets, debossed with “93” on one side and “7368” on the other in bottles of 30, 60, and 90.
Storage Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature].
Keep container tightly closed.
Protect from light.
Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure (as required).
Manufactured In Israel By: TEVA PHARMACEUTICAL IND.
LTD.
Jerusalem, 9777402, Israel Manufactured For: TEVA PHARMACEUTICALS USA, INC.
North Wales, PA 19454 Relabeled By: Proficient Rx LP Thousand Oaks, CA 91320 Rev.
I 10/2014

Quoted from the official label, section “How Supplied”.

What is in it

Losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg, losartan potassium and hydrochlorothiazide tablets USP, 100 mg/12.5 mg, and losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg combine an angiotensin II receptor (type AT 1 ) antagonist and a diuretic, hydrochlorothiazide.
Losartan potassium, a non-peptide molecule, is chemically described as 2-butyl-4-chloro-1-[ p- ( o -1 H -tetrazol-5-ylphenyl)benzyl]imidazole-5-methanol monopotassium salt.
Its structural formula is: C 22 H 22 ClKN 6 O M.W.
461.01 Losartan potassium is a white to off-white free-flowing crystalline powder.
It is freely soluble in water, soluble in alcohols, and slightly soluble in common organic solvents, such as acetonitrile and methyl ethyl ketone.
Oxidation of the 5-hydroxymethyl group on the imidazole ring results in the active metabolite of losartan.
Hydrochlorothiazide is 6-chloro-3,4-dihydro-2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide.
Its structural formula is: C 7 H 8 ClN 3 O 4 S 2 M.W.
297.74 Hydrochlorothiazide is a white, or practically white, crystalline powder, which is slightly soluble in water, but freely soluble in sodium hydroxide solution.
Losartan potassium and hydrochlorothiazide tablets USP are available for oral administration in three tablet combinations of losartan and hydrochlorothiazide.
Losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg contain 50 mg of losartan potassium and 12.5 mg of hydrochlorothiazide.
Losartan potassium and hydrochlorothiazide tablets USP, 100 mg/12.5 mg contain 100 mg of losartan potassium and 12.5 mg of hydrochlorothiazide.
Losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg contain 100 mg of losartan potassium and 25 mg of hydrochlorothiazide.
Inactive ingredients are:
lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol-part hydrolyzed, pregelatinized starch, talc, and titanium dioxide.
Additionally 50 mg/12.5 mg tablets contain D&C Yellow #10 (Aluminum Lake) and FD&C Blue #1 (Aluminum Lake). 100 mg/25 mg tablets contain D&C Yellow #10 (Aluminum Lake).
Losartan potassium and hydrochlorothiazide tablets USP, 50 mg/12.5 mg contain 4.24 mg (0.108 mEq) of potassium, losartan potassium and hydrochlorothiazide tablets USP, 100 mg/12.5 mg contain 8.48 mg (0.216 mEq) of potassium, and losartan potassium and hydrochlorothiazide tablets USP, 100 mg/25 mg contain 8.48 mg (0.216 mEq) of potassium.
Losartan Potassium structure HCTZ structure

Quoted from the official label, section “Description”.

Ingredients people check for

Lactose, gluten, dyes, sugars and other ingredients that matter with an allergy, intolerance or diet — as this product’s FDA label lists them.

Lactose: lactose monohydrateMilk sugar: matters with lactose intolerance or a milk allergy.
Titanium dioxidetitanium dioxideA whitening agent no longer allowed in food in the EU (E171).

Quoted from the FDA label. A label that does not name an ingredient is not a guarantee that the product is free of it, and formulations change. With an allergy, check the pack and ask a pharmacist.

Every version of this medicine (21)

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Same active substance, strength and form in other countries

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Canada7 matching products

Every strength and form (25)

Details

Made by	Proficient Rx LP
Active substance	Losartan Potassium and Hydrochlorothiazide
Used in	Heart, blood pressure and circulation
Strength	100 mg + 25 mg
Form	Tablet, Film Coated
Route	Oral
Packs	30 TABLET, FILM COATED in 1 BOTTLE · 60 TABLET, FILM COATED in 1 BOTTLE
NDC	63187-347
NDC	63187-602

Source: NDC Directory · 2026-09-13 · not reviewed by a clinician

Source: US Food and Drug Administration, NDC Directory. Reuse terms: US government work (FDA).

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Other strengths and forms

78 products are sold under this name. Grouped by form; a number on a strength means several companies make it.

Tablet, Film Coated71 products
- 12.5 mg + 50 mg4
  12.5 mg + 50 mg · 4 companies
- 12.5 mg + 100 mg2
  12.5 mg + 100 mg · 2 companies
  - Bryant Ranch Prepack
  - Unichem Pharmaceuticals (USA), Inc.
- 25 mg + 100 mg4
  25 mg + 100 mg · 4 companies
- 50 mg + 12.5 mg22
  50 mg + 12.5 mg · 22 companies
  +14 more
- 100 mg + 25 mg20
  100 mg + 25 mg · 20 companies
  +12 more
- 100 mg + 12.5 mg19
  100 mg + 12.5 mg · 19 companies
  +11 more
Tablet7 products
- 12.5 mg + 50 mg
- 12.5 mg + 100 mg2
  12.5 mg + 100 mg · 2 companies
  - Lupin Pharmaceuticals, Inc.
  - Preferred Pharmaceuticals Inc.
- 25 mg + 100 mg3
  25 mg + 100 mg · 3 companies
- 100 mg + 12.5 mg

Same active substance

These contain the same substance. That does not mean one can replace another — ask a pharmacist.

See every product with Losartan Potassium and Hydrochlorothiazide