Medicine guide

Atenolol and Chlorthalidone

50 mg + 25 mg · Tablet

Prescription only
Thiazide-like Diuretic

Active substance: Atenolol and Chlorthalidone
Used in: Heart, blood pressure and circulation
Made by: Zydus Pharmaceuticals USA Inc.
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 · 2024-01-08

What it is

Thiazide-like Diuretic

Used for

Atenolol and chlorthalidone tablets are indicated for the treatment of hypertension, to lower blood pressure.

The label’s usual adult dose

Chlorthalidone is usually given at a dose of 25 mg daily; the usual initial dose of atenolol is 50 mg daily.

Creatinine Clearance (mL/min/1.73m 2 ) Atenolol Elimination Half-Life (hrs.) Maximum Dosage 15 to 35 16 to 27 50 mg daily < 15 > 27 50 mg every other day

Full directions ↓

Do not take it if

Atenolol and chlorthalidone tablets are contraindicated in patients with:

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

14other products contain Atenolol and Chlorthalidone — compare makers, forms and strengths

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

What it is for

Atenolol and chlorthalidone tablets are indicated for the treatment of hypertension, to lower blood pressure.
Lowering blood pressure lowers the risk of fatal and non-fatal cardiovascular events, primarily strokes and myocardial infarctions.
These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including atenolol and chlorthalidone.
Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake.
Many patients will require more than 1 drug to achieve blood pressure goals.
For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program's Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC).
Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action, have been shown in randomized controlled trials to reduce cardiovascular morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits.
The largest and most consistent cardiovascular outcome benefit has been a reduction in the risk of stroke, but reductions in myocardial infarction and cardiovascular mortality also have been seen regularly.
Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit.
Relative risk reduction from blood pressure reduction is similar across populations with varying absolute risk, so the absolute benefit is greater in patients who are at higher risk independent of their hypertension (for example, patients with diabetes or hyperlipidemia), and such patients would be expected to benefit from more aggressive treatment to a lower blood pressure goal.
Some antihypertensive drugs have smaller blood pressure effects (as monotherapy) in black patients, and many antihypertensive drugs have additional approved indications and effects (e.g., on angina, heart failure, or diabetic kidney disease).
These considerations may guide selection of therapy.
This fixed dose combination drug is not indicated for initial therapy of hypertension.
If the fixed dose combination represents the dose appropriate to the individual patient's needs, it may be more convenient than the separate components.

From the official label · 2024-01-08 · DailyMed

How it works

From this product’s own US prescribing label.

Atenolol and Chlorthalidone Tablets Atenolol and chlorthalidone have been used singly and concomitantly for the treatment of hypertension.
The antihypertensive effects of these agents are additive, and studies have shown that there is no interference with bioavailability when these agents are given together in the single combination tablet.

Peak level after2–4 h

Half-life6–7 h

Mostly cleared after≈ 32.5 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

Unlike propranolol or metoprolol, but like nadolol, hydrophilic atenolol undergoes little or no metabolism by the liver, and the absorbed portion is eliminated primarily by renal excretion.

How it leaves the body

Approximately 50% of an oral dose is absorbed from the gastrointestinal tract, the remainder being excreted unchanged in the feces.

Quoted from the prescribing label, sections “Mechanism of Action” and “Pharmacokinetics”. DailyMed · 2024-01-08

Do not take it if

Atenolol and chlorthalidone tablets are contraindicated in patients with:
sinus bradycardia; heart block greater than first degree; cardiogenic shock; overt cardiac failure (see WARNINGS ); anuria; hypersensitivity to this product or to sulfonamide-derived drugs.

Quoted from the official label, section “Contraindications”.

How to take it

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

DOSAGE MUST BE INDIVIDUALIZED (See INDICATIONS AND USAGE ).
Chlorthalidone is usually given at a dose of 25 mg daily; the usual initial dose of atenolol is 50 mg daily.
Therefore, the initial dose should be one atenolol and chlorthalidone 50mg/25mg tablet given once a day.
If an optimal response is not achieved, the dosage should be increased to one atenolol and chlorthalidone 100mg/25mg tablet given once a day.
When necessary, another antihypertensive agent may be added gradually beginning with 50 percent of the usual recommended starting dose to
avoid an excessive fall in blood pressure.
Since atenolol is excreted via the kidneys, dosage should be adjusted in cases of severe impairment of renal function.
No significant accumulation of atenolol occurs until creatinine clearance falls below 35 mL/min/1.73m 2 (normal range is 100 mL/min/1.73m 2 to 150 mL/min/1.73m 2 ); therefore, the following maximum dosages are recommended for patients with renal impairment.
Creatinine Clearance (mL/min/1.73m 2 ) Atenolol Elimination Half-Life (hrs.) Maximum Dosage 15 to 35 16 to 27 50 mg daily < 15 > 27 50 mg every other day

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

Other warnings

Cardiac Failure Sympathetic stimulation is necessary in supporting circulatory function in congestive heart failure, and beta blockade carries the potential hazard of further depressing myocardial contractility and precipitating more severe failure.
IN PATIENTS WITHOUT A HISTORY OF CARDIAC FAILURE, continued depression of the myocardium with beta-blocking agents over a period of time can, in some cases, lead to cardiac failure.
At the first sign or symptom of impending cardiac failure, patients should be treated appropriately according to currently recommended guidelines, and the response observed closely.
If cardiac failure continues despite adequate treatment, atenolol and chlorthalidone tablets should be withdrawn (See DOSAGE AND ADMINISTRATION ).
Renal and Hepatic Disease and Electrolyte Disturbances Since atenolol is excreted via the kidneys, atenolol and chlorthalidone tablets should be used with caution in patients with impaired renal function.
In patients with renal disease, thiazides may precipitate azotemia.
Since cumulative effects may develop in the presence of impaired renal function, if progressive renal impairment becomes evident, atenolol and chlorthalidone tablets should be discontinued.
In patients with impaired hepatic function or progressive liver disease, minor alterations in fluid and electrolyte balance may precipitate hepatic coma.
Atenolol and chlorthalidone tablets should be used with caution in these patients.
Ischemic Heart Disease Following abrupt cessation of therapy with certain beta-blocking agents in patients with coronary artery disease, exacerbations of angina pectoris and, in some cases, myocardial infarction have been reported.
Therefore, such patients should be cautioned against interruption of therapy without the physician's advice.
Even in the absence of overt angina pectoris, when discontinuation of atenolol and chlorthalidone tablets is planned, the patient should be carefully observed and should be advised to limit physical activity to a minimum.
Atenolol and chlorthalidone tablets should be reinstated if withdrawal symptoms occur.
Because coronary artery disease is common and may be unrecognized, it may be prudent not to discontinue atenolol and chlorthalidone tablets therapy abruptly even in patients treated only for hypertension.
Concomitant Use of Calcium Channel Blockers Bradycardia and heart block can occur and the left ventricular end diastolic pressure can rise when beta-blockers are administered with verapamil or diltiazem.
Patients with pre-existing conduction abnormalities or left ventricular dysfunction are particularly susceptible (See PRECAUTIONS ).
Bronchospastic Diseases PATIENTS WITH BRONCHOSPASTIC DISEASE SHOULD, IN GENERAL, NOT RECEIVE BETA-BLOCKERS.
Because of its relative beta 1 -selectivity, however, atenolol and chlorthalidone tablets may be used with caution in patients with bronchospastic disease who do not respond to or cannot tolerate, other antihypertensive treatment.
Since beta 1 -selectivity is not absolute, the lowest possible dose of atenolol and chlorthalidone tablets should be used and a beta 2 -stimulating agent (bronchodilator) should be made available.
If dosage must be increased, dividing the dose should be considered in order to achieve lower peak blood levels.
Major Surgery Chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery, however the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures.
Metabolic and Endocrine Effects Beta-blockers may prevent early warning signs of hypoglycemia, such as tachycardia, and increase the risk for severe or prolonged hypoglycemia at any time during treatment, especially in patients with diabetes mellitus or children and patients who are fasting (i.e., surgery, not eating regularly, or are vomiting).
If severe hypoglycemia occurs, patients should be instructed to seek emergency treatment.
Insulin requirements in diabetic patients may be increased, decreased or unchanged; latent diabetes mellitus may become manifest during chlorthalidone administration.
Beta-adrenergic blockade may mask certain clinical signs (e.g., tachycardia) of hyperthyroidism.
Abrupt withdrawal of beta blockade might precipitate a thyroid storm; therefore, patients suspected of developing thyrotoxicosis from whom atenolol and chlorthalidone tablets therapy is to be withdrawn should be monitored closely.
Because calcium excretion is decreased by thiazides, atenolol and chlorthalidone tablets should be discontinued before carrying out tests for parathyroid function.
Pathologic changes in the parathyroid glands, with hypercalcemia and hypophosphatemia, have been observed in a few patients on prolonged thiazide therapy; however, the common complications of hyperparathyroidism such as renal lithiasis, bone resorption, and peptic ulceration have not been seen.
Hyperuricemia may occur, or acute gout may be precipitated in certain patients receiving thiazide therapy.
Untreated Pheochromocytoma Atenolol and chlorthalidone tablets should not be given to patients with untreated pheochromocytoma.
Pregnancy and Fetal Injury Atenolol can cause fetal harm when administered to a pregnant woman.
Atenolol crosses the placental barrier and appears in cord blood.
Administration of atenolol, starting in the second trimester of pregnancy, has been associated with the birth of infants that are small for gestational age.
No studies have been performed on the use of atenolol in the first trimester and the possibility of fetal injury cannot be excluded.
If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.
Caution should be exercised when atenolol and chlorthalidone tablets are administered during pregnancy or to a woman who is breastfeeding (See PRECAUTIONS, Nursing Mothers ).
Atenolol and chlorthalidone tablets were studied for teratogenic potential in the rat and rabbit.
Doses of atenolol/chlorthalidone of 8/2 mg/kg/day, 80/20 mg/kg/day, and 240/60 mg/kg/day were administered orally to pregnant rats with no evidence of embryofetotoxicity observed.
Two studies were conducted in rabbits.
In the first study, pregnant rabbits were dosed with 8/2 mg/kg/day, 80/20 mg/kg/day, and 160/40 mg/kg/day of atenolol/chlorthalidone.
No teratogenic effects were noted, but embryonic resorptions were observed at all dose levels (ranging from approximately 5 times to 100 times the maximum recommended human dose * ).
In the second rabbit study, doses of atenolol/chlorthalidone were 4/1 mg/kg/day, 8/2 mg/kg/day, and 20/5 mg/kg/day.
No teratogenic or embryotoxic effects were demonstrated.
Atenolol Atenolol has been shown to produce a dose-related increase in embryo/fetal resorptions in rats at doses equal to or greater than 50 mg/kg/day or 25 or more times the maximum recommended human antihypertensive dose. * Although similar effects were not seen in rabbits, the compound was not evaluated in rabbits at doses above 25 mg/kg/day or 12.5 times the maximum recommended human antihypertensive dose. * Chlorthalidone Thiazides cross the placental barrier and appear in cord blood.
The use of chlorthalidone and related drugs in pregnant women requires that the anticipated benefits of the drug be weighed against possible hazards to the fetus.
These hazards include fetal or neonatal jaundice, thrombocytopenia and possibly other adverse reactions which have occurred in the adult. * Based on the maximum dose of 100 mg/day in a 50 kg patient.
General Atenolol and chlorthalidone tablets may aggravate peripheral arterial circulatory disorders.
Information for Patients Hypoglycemia Inform patients or caregivers that there is a risk of hypoglycemia when atenolol and chlorthalidone tablets are given to patients who are fasting or who are vomiting.
Monitor for symptoms of hypoglycemia.
Electrolyte and Fluid Balance Status Periodic determination of serum electrolytes to detect possible electrolyte imbalance should be performed at appropriate intervals.
Patients should be observed for clinical signs of fluid or electrolyte imbalance; i.e., 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 include dryness of the mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, and gastrointestinal disturbances such as nausea and vomiting.
Measurement of potassium levels is appropriate especially in elderly patients, those receiving digitalis preparations for cardiac failure, patients whose dietary intake of potassium is abnormally low, or those suffering from gastrointestinal complaints.
Hypokalemia may develop especially with brisk diuresis, when severe cirrhosis is present, or during concomitant use of corticosteroids or ACTH.
Interference with adequate oral electrolyte intake will also contribute to hypokalemia.
Hypokalemia can sensitize or exaggerate the response of the heart to the toxic effects of digitalis (e.g., increased ventricular irritability).
Hypokalemia may be avoided or treated by use of potassium supplements or foods with a high potassium content.
Any chloride deficit during thiazide therapy is generally mild and usually does not require specific treatment except under extraordinary circumstances (as in liver disease or renal disease).
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.
Drug Interactions Atenolol and chlorthalidone tablets may potentiate the action of other antihypertensive agents used concomitantly.
Other Precautions In patients receiving thiazides, sensitivity reactions may occur with or without a history of allergy or bronchial asthma.
The possible exacerbation or activation of systemic lupus erythematosus has been reported.
The antihypertensive effects of thiazides may be enhanced in the postsympathectomy patient.
Carcinogenesis, Mutagenesis, Impairment of Fertility Two long-term (maximum dosing duration of 18 or 24 months) rat studies and one long-term (maximum dosing duration of 18 months) mouse study, each employing dose levels as high as 300 mg/kg/day or 150 times the maximum recommended human antihypertensive dose*, did not indicate a carcinogenic potential of atenolol.
A third (24 month) rat study, employing doses of 500 mg/kg/day and 1,500 mg/kg/day (250 and 750 times the maximum recommended human antihypertensive dose * ) resulted in increased incidences of benign adrenal medullary tumors in males and females, mammary fibroadenomas in females, and anterior pituitary adenomas and thyroid parafollicular cell carcinomas in males.
No evidence of a mutagenic potential of atenolol was uncovered in the dominant lethal test (mouse), in vivo cytogenetics test (Chinese hamster) or Ames test ( S typhimurium ).
Fertility of male or female rats (evaluated at dose levels as high as 200 mg/kg/day or 100 times the maximum recommended human dose * ) was unaffected by atenolol administration. * Based on the maximum dose of 100 mg/day in a 50 kg patient.
Animal Toxicology Six month oral administration studies were conducted in rats and dogs using atenolol and chlorthalidone tablets doses up to 12.5 mg/kg/day (atenolol/chlorthalidone 10/2.5 mg/kg/day -- approximately five times the maximum recommended human antihypertensive dose*).
There were no functional or morphological abnormalities resulting from dosing either compound alone or together other than minor changes in heart rate, blood pressure and urine chemistry which were attributed to the known pharmacologic properties of atenolol and/or chlorthalidone.
Chronic studies of atenolol performed in animals have revealed the occurrence of vacuolation of epithelial cells of Brunner's glands in the duodenum of both male and female dogs at all tested dose levels (starting at 15 mg/kg/day or 7.5 times the maximum recommended human antihypertensive dose * ) and increased incidence of atrial degeneration of hearts of male rats at 300 mg atenolol/kg/day but not 150 mg atenolol/kg/day (150 and 75 times the maximum recommended human antihypertensive dose, * respectively). *Based on the maximum dose of 100 mg/day in a 50 kg patient.
Pregnancy See WARNINGS - Pregnancy and Fetal Injury .
Nursing Mothers Atenolol is excreted in human breast milk at a ratio of 1.5 to 6.8 when compared to the concentration in plasma.
Pediatric Use Safety and effectiveness in pediatric patients have not been established.
Geriatric Use Clinical studies of atenolol and chlorthalidone tablets did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.

Quoted from the official label, section “Warnings”.

Pregnancy and breastfeeding

Atenolol is excreted in human breast milk at a ratio of 1.5 to 6.8 when compared to the concentration in plasma.
Caution should be exercised when atenolol is administered to a nursing woman.
Clinically significant bradycardia has been reported in breastfed infants.
Premature infants, or infants with impaired renal function, may be more likely to develop adverse effects.
Neonates born to mothers who are receiving atenolol at parturition or breastfeeding may be at risk for hypoglycemia and bradycardia.
Caution should be exercised when atenolol and chlorthalidone tablets are administered during pregnancy or to a woman who is breastfeeding (See WARNINGS, Pregnancy and Fetal Injury ).

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

Other medicines

Atenolol and chlorthalidone tablets may potentiate the action of other antihypertensive agents used concomitantly.
Patients treated with atenolol and chlorthalidone tablets plus a catecholamine depletor (e.g., reserpine) should be closely observed for evidence of hypotension and/or marked bradycardia which may produce vertigo, syncope or postural hypotension.
Calcium channel blockers may also have an additive effect when given with atenolol and chlorthalidone tablets (See WARNINGS ).
Disopyramide is a Type I antiarrhythmic drug with potent negative inotropic and chronotropic effects.
Disopyramide has been associated with severe bradycardia, asystole and heart failure when administered with beta-blockers.
Amiodarone is an antiarrhythmic agent with negative chronotropic properties that may be additive to those seen with beta-blockers.
Thiazides may decrease arterial responsiveness to norepinephrine.
This diminution is not sufficient to preclude the therapeutic effectiveness of norepinephrine.
Thiazides may increase the responsiveness to tubocurarine.
Concomitant use of prostaglandin synthase inhibiting drugs, e.g., indomethacin, may decrease the hypotensive effects of beta-blockers.
Lithium generally should not be given with diuretics because they reduce its renal clearance and add a high risk of lithium toxicity.
Read prescribing information for lithium preparations before use of such preparations with atenolol and chlorthalidone tablets.
Beta-blockers may exacerbate the rebound hypertension which can follow the withdrawal of clonidine.
If the two drugs are coadministered, the beta-blocker should be withdrawn several days before the gradual withdrawal of clonidine.
If replacing clonidine by beta-blocker therapy, the introduction of beta-blockers should be delayed for several days after clonidine administration has stopped.
While taking beta-blockers, patients with a history of anaphylactic reaction to a variety of allergens may have a more severe reaction on repeated challenge, either accidental, diagnostic or therapeutic.
Such patients may be unresponsive to the usual doses of epinephrine used to treat the allergic reaction.
Both digitalis glycosides and beta-blockers slow atrioventricular conduction and decrease heart rate.
Concomitant use can increase the risk of bradycardia.

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.

No specific information is available with regard to overdosage and atenolol and chlorthalidone tablets in humans.
Treatment should be symptomatic and supportive and directed to the removal of any unabsorbed drug by induced emesis, or administration of activated charcoal.
Atenolol can be removed from the general circulation by hemodialysis.
Further consideration should be given to dehydration, electrolyte imbalance and hypotension by established procedures.
Atenolol Overdosage with atenolol has been reported with patients surviving acute doses as high as 5 g.
One death was reported in a man who may have taken as much as 10 g acutely.
The predominant symptoms reported following atenolol overdose are lethargy, disorder of respiratory drive, wheezing, sinus pause, and bradycardia.
Additionally, common effects associated with overdosage of any beta-adrenergic blocking agent are congestive heart failure, hypotension, bronchospasm, and/or hypoglycemia.
Other treatment modalities should be employed at the physician's discretion and may include:
BRADYCARDIA Atropine 1 mg to 2 mg intravenously.
If there is no response to vagal blockade, give isoproterenol cautiously.
In refractory cases, a transvenous cardiac pacemaker may be indicated.
Glucagon in a 10 mg intravenous bolus has been reported to be useful.
If required, this may be repeated or followed by an intravenous infusion of glucagon 1 mg/h to 10 mg/h depending on response.
HEART BLOCK (SECOND OR THIRD DEGREE) Isoproterenol or transvenous pacemaker.
CONGESTIVE HEART FAILURE Digitalize the patient and administer a diuretic.
Glucagon has been reported to be useful.
HYPOTENSION Vasopressors such as dopamine or norepinephrine (levarterenol).
Monitor blood pressure continuously.
BRONCHOSPASM A beta 2 -stimulant such as isoproterenol or terbutaline and/or aminophylline.
HYPOGLYCEMIA Intravenous glucose.
ELECTROLYTE DISTURBANCE Monitor electrolyte levels and renal function.
Institute measures to maintain hydration and electrolytes.
Based on the severity of symptoms, management may require intensive support care and facilities for applying cardiac and respiratory support.
Chlorthalidone Symptoms of chlorthalidone overdose include nausea, weakness, dizziness and disturbances of electrolyte balance.

Quoted from the official label, section “Overdosage”.

Use in children

Safety and effectiveness in pediatric patients have not been established.

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

Use in older people

Clinical studies of atenolol and chlorthalidone tablets did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.
Other reported clinical experience has not identified differences in responses between the elderly and younger patients.
In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and concomitant disease or other drug therapy.

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

Side effects

Atenolol and chlorthalidone tablets are usually well tolerated in properly selected patients.
Most adverse effects have been mild and transient.
The adverse effects observed for atenolol and chlorthalidone tablets are essentially the same as those seen with the individual components.
Atenolol The frequency estimates in the following table were derived from controlled studies in which adverse reactions were either volunteered by the patient (US studies) or elicited, e.g., by checklist (foreign studies).
The reported frequency of elicited adverse effects was higher for both atenolol and placebo-treated patients than when these reactions were volunteered.
Where frequency of adverse effects for atenolol and placebo is similar, causal relationship to atenolol is uncertain.
Volunteered (US Studies) Total-Volunteered and Elicited (Foreign + US Studies) Atenolol (n = 164) % Placebo (n = 206) % Atenolol (n = 399) % Placebo (n = 407) % CARDIOVASCULAR Bradycardia 3 0 3 0 Cold Extremities 0 0.5 12 5 Postural Hypotension 2 1 4 5 Leg Pain 0 0.5 3 1 CENTRAL NERVOUS SYSTEM / NEUROMUSCULAR Dizziness 4 1 13 6 Vertigo 2 0.5 2
Light-Headedness 1 0 3
0.7 Tiredness 0.6 0.5 26 13 Fatigue 3 1 6 5 Lethargy 1 0 3
0.7 Drowsiness 0.6 0 2
0.5 Depression 0.6 0.5 12 9 Dreaming 0 0 3 1 GASTROINTESTINAL Diarrhea 2 0 3 2 Nausea 4 1 3 1 RESPIRATORY (see Warnings ) Wheeziness 0 0 3 3 Dyspnea 0.6 1 6 4 During postmarketing experience, the following have been reported in temporal relationship to the use of the drug:
elevated liver enzymes and/or bilirubin, hallucinations, headache, impotence, Peyronie's disease, postural hypotension which may be associated with syncope, psoriasiform rash or exacerbation of psoriasis, psychoses, purpura, reversible alopecia, thrombocytopenia, visual disturbance, sick sinus syndrome, and dry mouth.
Atenolol and chlorthalidone tablet, like other beta-blockers, has been associated with the development of antinuclear antibodies (ANA), lupus syndrome, and Raynaud's phenomenon.
Chlorthalidone Cardiovascular: orthostatic hypotension;
Gastrointestinal:
anorexia, gastric irritation, vomiting, cramping, constipation, jaundice (intrahepatic cholestatic jaundice), pancreatitis;
CNS: vertigo, paresthesia, xanthopsia;
Hematologic: leukopenia, agranulocytosis, thrombocytopenia, aplastic anemia;
Hypersensitivity:
purpura, photosensitivity, rash, urticaria, necrotizing angiitis (vasculitis) (cutaneous vasculitis), Lyell's syndrome (toxic epidermal necrolysis);
Miscellaneous:
hyperglycemia, glycosuria, hyperuricemia, muscle spasm, weakness, restlessness.
Clinical trials of atenolol and chlorthalidone tablets conducted in the United States (89 patients treated with atenolol and chlorthalidone tablets) revealed no new or unexpected adverse effects.

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

What it looks like and how it is packed

Atenolol and Chlorthalidone Tablets, USP are uncoated tablets.
Atenolol and Chlorthalidone Tablets USP, 50 mg/25 mg are white to off white, round, biconvex, bevelled tablets, with debossing of '11' above breakline and '67' below breakline on one side and plain on the other side and are supplied as follows:
NDC 70710-1167-1 in bottle of 100 tablets with child-resistant closure Atenolol and Chlorthalidone Tablets USP, 100 mg/25 mg are white to off white, round, biconvex, beveled tablets, with debossing of '11' over '68' on one side and plain on the other side and are supplied as follows:
NDC 70710-1168-1 in bottle of 100 tablets with child-resistant closure
Store at 20°C to 25°C (68°F to 77°F) [See USP Controlled Room Temperature].
Dispense in well-closed, light-resistant containers.
Call your doctor for medical advice about side effects.
You may report side effects to FDA at 1-800-FDA-1088.
Please address medical inquiries to, MedicalAffairs@zydususa.com or Tel.:
1-877-993-8779 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

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

What is in it

Atenolol and chlorthalidone tablets are for the treatment of hypertension.
It combines the antihypertensive activity of two agents:
a beta 1 -selective (cardioselective) hydrophilic blocking agent (atenolol) and a monosulfonamyl diuretic (chlorthalidone).
Atenolol is Benzeneacetamide, 4-[2'-hydroxy-3'-[(1-methylethyl) amino] propoxy].
Atenolol, USP is a white or almost white powder and is sparingly soluble in water; soluble in absolute alcohol and practically insoluble in ether.
Chlorthalidone is 2-Chloro-5-(1-hydroxy-3-oxo-1-isoindolinyl) benzene sulfonamide:
Chlorthalidone, USP is white to yellowish crystalline powder.
Each atenolol and chlorthalidone tablet, USP intended for oral administration contains atenolol 50 mg or 100 mg and chlorthalidone 25 mg.
In addition, each uncoated tablet contains the following inactive ingredients:
citric acid, colloidal silicon dioxide, croscarmellose sodium, magnesium stearate, pregelatinized starch and silicified microcrystalline cellulose.
Atenolol Chlorthalidon Tablets, USP Atenolol Chlorthalidon Tablets, USP

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.

This label’s list of inactive ingredients names none of: lactose, wheat or gluten, colour dyes, sugars, sugar alcohols, alcohol (ethanol), aspartame (phenylalanine), gelatin, peanut oil, soy, parabens, sulfites, titanium dioxide.

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 (7)

The same active substance, strength and kind of form, from every company that sells it — with what each label lists.

Showing 7 of 7

Same active substance, strength and form in other countries

Matched on active substance, strength and kind of form only. This is not a statement that the products are equivalent or interchangeable: other ingredients, release and approved uses can differ — ask a pharmacist before swapping.

Medicine passport: one printable page to show a pharmacist abroad

Canada1 matching products

AA-ATENIDONE 50 mg + 25 mg · tablet

Every strength and form (2)

Details

Made by	Zydus Pharmaceuticals USA Inc.
Active substance	Atenolol and Chlorthalidone
Used in	Heart, blood pressure and circulation
Strength	50 mg + 25 mg
Form	Tablet
Route	Oral
Packs	100 TABLET in 1 BOTTLE
NDC	70710-1167

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).

Report wrong or outdated information on this page

Other strengths and forms

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

Tablet17 products
- 25 mg + 50 mg
- 50 mg + 25 mg7
  50 mg + 25 mg · 7 companies
  - Actavis Pharma, Inc.
  - ANI Pharmaceuticals, Inc.
  - Northstar Rx LLC.
  - PD-Rx Pharmaceuticals, Inc.
  - Unichem Pharmaceuticals (USA), Inc.
  - Zydus Lifesciences Limited
  - Zydus Pharmaceuticals USA Inc. · this page
- 100 mg + 25 mg9
  100 mg + 25 mg · 9 companies
  +1 more

Same active substance

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

See every product with Atenolol and Chlorthalidone