Medicine guide

Sulfamethoxazole and Trimethoprim

800 mg + 160 mg · Tablet

Prescription only
Dihydrofolate Reductase Inhibitor Antibacterial

Active substance: Sulfamethoxazole and Trimethoprim
Used in: Antibiotics, antivirals and antifungals taken into the body
Made by: Vista Pharmaceuticals, 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 · 2020-01-22

What it is

Dihydrofolate Reductase Inhibitor Antibacterial

Used for

To reduce the development of drug-resistant bacteria and maintain the effectiveness of sulfamethoxazole and trimethoprim tablets and other antibacterial drugs, sulfamethoxazole and trimethoprim tablets should…

The label’s usual adult dose

The recommended dose for Children R with urinary tract infections or acute otitis media is 40 mg/kg sulfamethoxazole and 8 mg/kg trimethoprim per 24 hours, given in two divided doses every 12 hours for 10 days.

Full directions ↓

Do not take it if

Sulfamethoxazole and trimethoprim is contraindicated in patients with a known hypersensitivity to trimethoprim or sulfonamides and in patients with documented megaloblastic anemia due to folate deficiency.

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

65other products contain Sulfamethoxazole and Trimethoprim — compare makers, forms and strengths

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

What it is for

Urinary Tract Infections:

To reduce the development of drug-resistant bacteria and maintain the effectiveness of sulfamethoxazole and trimethoprim tablets and other antibacterial drugs, sulfamethoxazole and trimethoprim tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria R .
When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy.
In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
For the treatment of urinary tract infections due to susceptible strains of the following organisms:
Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis and Proteus vulgaris.
It is recommended that initial episodes of uncomplicated urinary tract infections be treated with a single effective antibacterial agent rather than the combination.
Acute Otitis Media:
For the treatment of acute otitis media in pediatric patients due to susceptible strains of pneumoniae or Haemophilus influenzae when in the judgment of the physician sulfamethoxazole and trimethoprim offers some advantage over the use of other antimicrobial agents.
To date, there are limited data on the safety of repeated use of sulfamethoxazole and trimethoprim in pediatric patients under two years of age.
Sulfamethoxazole and trimethoprim is not indicated for prophylactic or prolonged administration in otitis media at any age.
Acute Exacerbations of Chronic Bronchitis in
Adults:
For the treatment of acute exacerbations of chronic bronchitis due to susceptible strains of Streptococcus pneumoniae or Haemophilus influenzae when in the judgment of the physician sulfamethoxazole and trimethoprim offers some advantage over the use of a single antimicrobial agent.
Shigellosis:
For the treatment of enteritis caused by susceptible strains of Shigella flexneri and Shigella sonnei when antibacterial therapy is indicated.
Pneumocystis Carinii Pneumonia:
For the treatment of documented Pneumocystis carinii pneumonia and for prophylaxis against Pneumocystis carinii pneumonia in individuals who are immunosuppressed and considered to be at an increased risk of developing Pneumocystis carinii pneumonia.
Traveler’s Diarrhea in
Adults:
For the treatment of traveler’s diarrhea due to susceptible strains of enterotoxigenic E. coli.

From the official label · 2020-01-22 · DailyMed

How it works

From this product’s own US prescribing label.

Sulfamethoxazole and trimethoprim is rapidly absorbed following oral administration.
Both sulfamethoxazole and trimethoprim exist in the blood as unbound, protein-bound and metabolized forms. sulfamethoxazole also exists as the conjugated form.

Peak level after1–4 h

How the body breaks it down

Both sulfamethoxazole and trimethoprim exist in the blood as unbound, protein-bound and metabolized forms. sulfamethoxazole also exists as the conjugated form.

Quoted from the prescribing label, sections “Mechanism of Action” and “Pharmacokinetics”. DailyMed · 2020-01-22

Do not take it if

Sulfamethoxazole and trimethoprim is contraindicated in patients with a known hypersensitivity to trimethoprim or sulfonamides and in patients with documented megaloblastic anemia due to folate deficiency.
Sulfamethoxazole and trimethoprim is also contraindicated in pregnant patients and nursing mothers, because sulfonamides pass the placenta and are excreted in the milk and may cause kernicterus.
Sulfamethoxazole and trimethoprim is contraindicated in pediatric patients less than 2 months of age.
Sulfamethoxazole and trimethoprim is also contraindicated in patients with marked hepatic damage or with severe renal insufficiency when renal function status cannot be monitored.

Quoted from the official label, section “Contraindications”.

How to take it

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

Not recommended for use in pediatric patients less than 2 months of age.
Urinary Tract Infections and Shigellosis in
Adults and Pediatric Patients, and Acute Otitis Media in Children R
Adults:
The usual adult dosage in the treatment of urinary tract infections is 1 sulfamethoxazole and trimethoprim Double Strength tablet or 2 sulfamethoxazole and trimethoprim tablets every 12 hours for 10 to 14 days.
An identical daily dosage is used for 5 days in the treatment of shigellosis.
Children R :
The recommended dose for Children R with urinary tract infections or acute otitis media is 40 mg/kg sulfamethoxazole and 8 mg/kg trimethoprim per 24 hours, given in two divided doses every 12 hours for 10 days.
An identical daily dosage is used for 5 days in the treatment of shigellosis.
The following table is a guideline for the attainment of this dosage:
Children R 2 months of age and older:
Weight Dose – every 12 hours lb kg Tablets 22 10 - 44 20 1 66 30 1½ 88 40 2 or 1 Double Strength tablet For Patients with Impaired Renal Function:
When renal function is impaired, a reduced dosage should be employed using the following table:
Creatinine Recommended Clearance (mL/min) Dosage Regimen Above 30 Usual standard regimen 15-30 1/2 the usual regimen Below 15 Use not recommended Acute Exacerbations of Chronic Bronchitis in
Adults:
The usual adult dosage in the treatment of acute exacerbations of chronic bronchitis is 1 sulfamethoxazole and trimethoprim Double Strength tablet or 2 sulfamethoxazole and trimethoprim tablets every 12 hours for 14 days.
Pneumocystis Carinii Pneumonia:
Treatment:
Adults and Children R :
The recommended dosage for patients with documented Pneumocystis carinii pneumonia is 75 to 100 mg/kg sulfamethoxazole and 15 to 20 mg/kg trimethoprim per 24 hours given in equally divided doses every 6 hours for 14 to 21 days11.
The following table is a guideline for the upper limit of this dosage.
Weight Dose – every 6 hours lb kg Tablets 18 8 - 35 16 1 53 24 1 ½ 70 32 2 or 1 Double Strength tablet 88 40 2 ½ 106 48 3 or 1 ½ Double Strength tablets 141 64 4 or 2 Double Strength tablets 176 80 5 or 2 ½ Double Strength tablets For the lower limit dose (75 mg/kg sulfamethoxazole and 15 mg/kg trimethoprim per 24 hours) administer 75% of the dose in the above table.
Prophylaxis:
Adults:
The recommended dosage for prophylaxis in
adults is 1 sulfamethoxazole and trimethoprim Double Strength tablet daily 12R Children R :
For Children R , the recommended dose is 750 mg/m 2 /day sulfamethoxazole with 150 mg/m 2 /day trimethoprim given orally in equally divided doses twice a day, on 3 consecutive days per week.
The total daily dose should not exceed 1600 mg sulfamethoxazole and 320 mg trimethoprim 13R The following table is a guideline for the attainment of this dosage in Children R :
Body Surface Area Dose – every 12 hours (m 2 ) Tablets 0.26 - 0.53 ½ 1.06 1 Traveler’s Diarrhea in
Adults:
For the treatment of traveler’s diarrhea, the usual adult dosage is 1 sulfamethoxazole and trimethoprim Double Strength tablet or 2 sulfamethoxazole and trimethoprim tablets every 12 hours for 5 days.

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

Other warnings

SULFONAMIDES, INCLUDING SULFONAMIDE-CONTAINING PRODUCTS SUCH AS SULFAMETHOXAZOLE/TRIMETHOPRIM, SHOULD BE DISCONTINUED AT THE FIRST APPEARANCE OF SKIN RASH OR ANY SIGN OF ADVERSE REACTION.
In rare instances, a skin rash may be followed by a more severe reaction, such as Stevens-Johnson syndrome, toxic epidermal necrolysis, hepatic necrosis, and serious blood disorders (see PRECAUTIONS).
Clinical signs, such as rash, sore throat, fever, arthralgia, pallor, purpura or jaundice may be early indications of serious reactions.
Cough, shortness of breath, and pulmonary infiltrates are hypersensitivity reactions of the respiratory tract that have been reported in association with sulfonamide treatment.
The sulfonamides should not be used for the treatment of group A - B hemolytic streptococcal infections.
In an established infection, they will not eradicate the streptococcus and, therefore, will not prevent sequelae such as rheumatic fever.
Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including sulfamethoxazole and trimethoprim tablets, and may range in severity from mild diarrhea to fatal colitis.
Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile A .
C. difficile produces toxins A and B which contribute to the development of CDAD.
Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy.
CDAD must be considered in all patients who present with diarrhea following antibiotic use.
Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents A .
If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued.
Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated A .
General:
Prescribing sulfamethoxazole and trimethoprim tablets in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria R .
Sulfamethoxazole and trimethoprim should be given with caution to patients with impaired renal or hepatic function, to those with possible folate deficiency (e.g., the elderly, chronic alcoholics, patients receiving anticonvulsant therapy, patients with malabsorption syndrome, and patients in malnutrition states) and to those with severe allergies or bronchial asthma.
In glucose-6-phosphate dehydrogenase deficient individuals, hemolysis may occur.
This reaction is frequently dose-related.
(see CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION).
Cases of hypoglycemia in non-diabetic patients treated with sulfamethoxazole and trimethoprim are seen rarely, usually occurring after a few days of therapy.
Patients with renal dysfunction, liver disease, malnutrition or those receiving high doses of sulfamethoxazole and trimethoprim are particularly at risk.
Hematological changes indicative of folic acid deficiency may occur in elderly patients or in patients with preexisting folic acid deficiency or kidney failure.
These effects are reversible by folinic acid therapy.
Trimethoprim has been noted to impair phenylalanine metabolism but this is of no significance in phenylketonuric patients on appropriate dietary restriction.
As with all drugs containing sulfonamides, caution is advisable in patients with porphyria or thyroid dysfunction.
AIDS patients may not tolerate or respond to sulfamethoxazole and trimethoprim in the same manner as non-AIDS patients.
The incidence of side effects, particularly rash, fever, leukopenia and elevated aminotransferase (transaminase) values, with sulfamethoxazole and trimethoprim therapy in AIDS patients who are being treated for Pneumocystis carinii pneumonia has been reported to be greatly increased compared with the incidence normally associated with the use of sulfamethoxazole and trimethoprim in non-AIDS patients.
The incidence of hyperkalemia appears to be increased in AIDS patients receiving sulfamethoxazole and trimethoprim.
Adverse effects are generally less severe in patients receiving sulfamethoxazole and trimethoprim for prophylaxis.
A history of mild intolerance to sulfamethoxazole and trimethoprim in AIDS patients does not appear to predict intolerance of subsequent secondary prophylaxis. 6 However, if a patient develops skin rash or any sign of adverse reaction, therapy with sulfamethoxazole and trimethoprim should be reevaluated (see WARNINGS).
High dosage of trimethoprim, as used in patients with Pneumocystis carinii pneumonia, induces a progressive but reversible increase of serum potassium concentrations in a substantial number of patients.
Even treatment with recommended doses may cause hyperkalemia when trimethoprim is administered to patients with underlying disorders of potassium metabolism, with renal insufficiency, or if drugs known to induce hyperkalemia are given concomitantly.
Close monitoring of serum potassium is warranted in these patients.
During treatment, adequate fluid intake and urinary output should be ensured to prevent crystalluria.
Patients who are “slow acetylators” may be more prone to idiosyncratic reactions to sulfonamides.
Information for Patients:
Patients should be counseled that antibacterial drugs including sulfamethoxazole and trimethoprim tablets should only be used to treat bacterial infections.
They do not treat viral infections (e.g., the common cold).When sulfamethoxazole and trimethoprim tablets are prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed.
Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by sulfamethoxazole and trimethoprim tablets or other antibacterial drugs in the future.
Patients should be instructed to maintain an adequate fluid intake in order to prevent crystalluria and stone formation.
Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued.
Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic.
If this occurs, patients should contact their physician as soon as possible.
Laboratory Tests:
Complete blood counts should be done frequently in patients receiving sulfamethoxazole and trimethoprim; if a significant reduction in the count of any formed blood element is noted, sulfamethoxazole and trimethoprim should be discontinued.
Urinalyses with careful microscopic examination and renal function tests should be performed during therapy, particularly for those patients with impaired renal function.
Drug Interactions:
In elderly patients concurrently receiving certain diuretics, primarily thiazides, an increased incidence of thrombocytopenia with purpura has been reported.
It has been reported that sulfamethoxazole and trimethoprim may prolong the prothrombin time in patients who are receiving the anticoagulant warfarin.
This interaction should be kept in mind when sulfamethoxazole and trimethoprim is given to patients already on anticoagulant therapy, and the coagulation time should be reassessed.
Sulfamethoxazole and trimethoprim may inhibit the hepatic metabolism of phenytoin.
Sulfamethoxazole and trimethoprim, given at a common clinical dosage, increased the phenytoin half-life by 39% and decreased the phenytoin metabolic clearance rate by 27%.
When administering these drugs concurrently, one should be alert for possible excessive phenytoin effect.
Sulfonamides can also displace methotrexate from plasma protein binding sites and can compete with the renal transport of methotrexate, thus increasing free methotrexate concentrations.
There have been reports of marked but reversible nephrotoxicity with co-administration of sulfamethoxazole and trimethoprim and cyclosporine in renal transplant recipients.
Increased digoxin blood levels can occur with concomitant sulfamethoxazole and trimethoprim therapy, especially in elderly patients.
Serum digoxin levels should be monitored.
Increased sulfamethoxazole blood levels may occur in patients who are receiving indomethacin.
Occasional reports suggest that patients receiving pyrimethamine as malaria prophylaxis in doses exceeding 25 mg weekly may develop megaloblastic anemia if sulfamethoxazole and trimethoprim is prescribed.
The efficacy of tricyclic antidepressants can decrease when coadministered with sulfamethoxazole and trimethoprim.
Like other sulfonamide-containing drugs, sulfamethoxazole and trimethoprim potentiates the effect of oral hypoglycemics.
In the literature, a single case of toxic delirium has been reported after concomitant intake of sulfamethoxazole/trimethoprim and amantadine.
In the literature, three cases of hyperkalemia in elderly patients have been reported after concomitant intake of trimethoprim/sulfamethoxazole and an angiotensin converting enzyme inhibitor. 8,9R Drug/Laboratory Test Interactions:
Sulfamethoxazole and trimethoprim, specifically the trimethoprim component, can interfere with a serum methotrexate assay as determined by the competitive binding protein technique (CBPA) when a bacterial dihydrofolate reductase is used as the binding protein.
No interference occurs, however, if methotrexate is measured by a radioimmunoassay (RIA).
The presence of sulfamethoxazole and trimethoprim may also interfere with the Jaffé alkaline picrate reaction assay for creatinine, resulting in over estimations of about 10% in the range of normal values.
Carcinogenesis, Mutagenesis, Impairment of Fertility:
Carcinogenesis:
Long-term studies in animals to evaluate carcinogenic potential have not been conducted with sulfamethoxazole and trimethoprim.
Mutagenesis:
Bacterial mutagenic studies have not been performed with sulfamethoxazole and trimethoprim in combination.
Trimethoprim was demonstrated to be nonmutagenic in the Ames assay.
No chromosomal damage was observed in human leukocytes in vitro with sulfamethoxazole and trimethoprim alone or in combination; the concentrations used exceeded blood levels of these compounds following therapy with sulfamethoxazole and trimethoprim.
Observations of leukocytes obtained from patients treated with sulfamethoxazole and trimethoprim revealed no chromosomal abnormalities.
Impairment of Fertility:
No adverse effects on fertility or general reproductive performance were observed in rats given oral dosages as high as 350 mg/kg/day sulfamethoxazole plus 70 mg/kg/day trimethoprim.
Pregnancy: Teratogenic Effects: Pregnancy Category C.
In rats, oral doses of 533 mg/kg sulfamethoxazole or 200 mg/kg trimethoprim produced teratologic effects manifested mainly as cleft palates.
The highest dose which did not cause cleft palates in rats was 512 mg/kg sulfamethoxazole or 192 mg/kg trimethoprim when administered separately.
In two studies in rats, no teratology was observed when 512 mg/kg of sulfamethoxazole was used in combination with 128 mg/kg of trimethoprim.
In one study, however, cleft palates were observed in one litter out of 9 when 355 mg/kg of sulfamethoxazole was used in combination with 88 mg/kg of trimethoprim.
In some rabbit studies, an overall increase in fetal loss (dead and resorbed and malformed conceptuses) was associated with doses of trimethoprim 6 times the human therapeutic dose.
While there are no large, well controlled studies on the use of sulfamethoxazole and trimethoprim in pregnant women, Brumfitt and Pursell, 10R in a retrospective study, reported the outcome of 186 pregnancies during which the mother received either placebo or sulfamethoxazole and trimethoprim.
The incidence of congenital abnormalities was 4.5% (3 of 66) in those who received placebo and 3.3% (4 of 120) in those receiving sulfamethoxazole/trimethoprim.
There were no abnormalities in the 10 children whose mothers received the drug during the first trimester.
In a separate survey, Brumfitt and Pursell also found no congenital abnormalities in 35 children whose mothers had received oral sulfamethoxazole and trimethoprim at the time of conception or shortly thereafter.
Because sulfamethoxazole and trimethoprim may interfere with folic acid metabolism, sulfamethoxazole and trimethoprim should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Nonteratogenic Effects: See CONTRAINDICATIONS section.
Nursing Mothers: See CONTRAINDICATIONS section.
Pediatric Use:
Sulfamethoxazole and trimethoprim is not recommended for infants R younger than 2 months of age (see INDICATIONS and CONTRAINDICATIONS sections).
Geriatric Use:
Clinical studies of sulfamethoxazole and trimethoprim did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.
There may be an increased risk of severe adverse reactions in elderly patients, particularly when complicating conditions exist, e.g., impaired kidney and/or liver function, possible folate deficiency, or concomitant use of other drugs.
Severe skin reactions, generalized bone marrow suppression (see WARNINGS and ADVERSE REACTIONS sections), a specific decrease in platelets (with or without purpura), and hyperkalemia are the most frequently reported severe adverse reactions in elderly patients.
In those concurrently receiving certain diuretics, primarily thiazides, an increased incidence of thrombocytopenia with purpura has been reported.
Increased digoxin blood levels can occur with concomitant sulfamethoxazole and trimethoprim therapy, especially in elderly patients.
Serum digoxin levels should be monitored.
Hematological changes indicative of folic acid deficiency may occur in elderly patients.
These effects are reversible by folinic acid therapy.
Appropriate dosage adjustments should be made for patients with impaired kidney function and duration of use should be as short as possible to minimize risks of undesired reactions (see DOSAGE AND ADMINISTRATION section).
The trimethoprim component of sulfamethoxazole and trimethoprim may cause hyperkalemia when administered to patients with underlying disorders of potassium metabolism, with renal insufficiency, or when given concomitantly with drugs known to induce hyperkalemia, such as angiotensin converting enzyme inhibitors.
Close monitoring of serum potassium is warranted in these patients.
Discontinuation of sulfamethoxazole and trimethoprim treatment is recommended to help lower potassium serum levels.
Sulfamethoxazole and Trimethoprim tablets contain 0.515 mg (0.023 mEq) of sodium per tablet.
Sulfamethoxazole and trimethoprim Double Strength Tablets contain 1.03 mg (0.046 mEq) of sodium per tablet.
Pharmacokinetics parameters for sulfamethoxazole were similar for geriatric subjects and younger adult subjects.
The mean maximum serum trimethoprim concentration was higher and mean renal clearance of trimethoprim was lower in geriatric subjects compared with younger subjects (see CLINICAL PHARMACOLOGY:
Geriatric Pharmacokinetics).

Quoted from the official label, section “Warnings”.

If you take too much

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

Acute:
The amount of a single dose of sulfamethoxazole and trimethoprim that is either associated with symptoms of overdosage or is likely to be life-threatening has not been reported.
Signs and symptoms of overdosage reported with sulfonamides include anorexia, colic, nausea, vomiting, dizziness, headache, drowsiness and unconsciousness.
Pyrexia, hematuria and crystalluria may be noted.
Blood dyscrasias and jaundice are potential late manifestations of overdosage.
Signs of acute overdosage with trimethoprim include nausea, vomiting, dizziness, headache, mental depression, confusion and bone marrow depression.
General principles of treatment include the institution of gastric lavage or emesis, forcing oral fluids, and the administration of intravenous fluids if urine output is low and renal function is normal.
Acidification of the urine will increase renal elimination of trimethoprim.
The patient should be monitored with blood counts and appropriate blood chemistries, including electrolytes.
If a significant blood dyscrasia or jaundice occurs, specific therapy should be instituted for these complications.
Peritoneal dialysis is not effective and hemodialysis is only moderately effective in eliminating sulfamethoxazole and trimethoprim.
Chronic:
Use of sulfamethoxazole and trimethoprim at high doses and/or for extended periods of time may cause bone marrow depression manifested as thrombocytopenia, leukopenia and/or megaloblastic anemia.
If signs of bone marrow depression occur, the patient should be given leucovorin 5 to 15 mg daily until normal hematopoiesis is restored.

Quoted from the official label, section “Overdosage”.

Side effects

The most common adverse effects are gastrointestinal disturbances (nausea, vomiting, anorexia) and allergic skin reactions (such as rash and urticaria).
FATALITIES ASSOCIATED WITH THE ADMINISTRATION OF SULFONAMIDES, ALTHOUGH RARE, HAVE OCCURRED DUE TO SEVERE REACTIONS, INCLUDING STEVENS-JOHNSON SYNDROME, TOXIC EPIDERMAL NECROLYSIS, FULMINANT HEPATIC NECROSIS, AGRANULOCYTOSIS, APLASTIC ANEMIA AND OTHER BLOOD DYSCRASIAS (SEE WARNINGS SECTION).
Hematologic:
Agranulocytosis, aplastic anemia, thrombocytopenia, leukopenia, neutropenia, hemolytic anemia, megaloblastic anemia, hypoprothrombinemia, methemoglobinemia, eosinophilia.
Allergic Reactions:
Stevens-Johnson syndrome, toxic epidermal necrolysis, anaphylaxis, allergic myocarditis, erythema multiforme, exfoliative dermatitis, angioedema, drug fever, chills, Henoch-Schoenlein purpura, serum sickness-like syndrome, generalized allergic reactions, generalized skin eruptions, photosensitivity, conjunctival and scleral injection, pruritus, urticaria and rash.
In addition, periarteritis nodosa and systemic lupus erythematosus have been reported.
Gastrointestinal:
Hepatitis (including cholestatic jaundice and hepatic necrosis), elevation of serum transaminase and bilirubin, pseudomembranous enterocolitis, pancreatitis, stomatitis, glossitis, nausea, emesis, abdominal pain, diarrhea, anorexia.
Genitourinary:
Renal failure, interstitial nephritis, BUN and serum creatinine elevation, toxic nephrosis with oliguria and anuria, crystalluria and nephrotoxicity in association with cyclosporine.
Metabolic and Nutritional:
Hyperkalemia (see PRECAUTIONS:
Use in the Treatment of and Prophylaxis for Pneumocystis Carinii Pneumonia in Patients with Acquired Immunodeficiency Syndrome (AIDS).
Neurologic:
Aseptic meningitis, convulsions, peripheral neuritis, ataxia, vertigo, tinnitus, headache.
Psychiatric: Hallucinations, depression, apathy, nervousness.
Endocrine:
The sulfonamides bear certain chemical similarities to some goitrogens, diuretics (acetazolamide and the thiazides) and oral hypoglycemic agents.
Cross-sensitivity may exist with these agents.
Diuresis and hypoglycemia have occurred rarely in patients receiving sulfonamides.
Musculoskeletal: Arthralgia and myalgia.
Isolated cases of rhabdomyolysis have been reported with sulfamethoxazole and trimethoprim, mainly in AIDS patients.
Respiratory: Cough, shortness of breath and R pulmonary infiltrates (see WARNINGS).
Miscellaneous : Weakness, fatigue, insomnia.

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

What it looks like and how it is packed

Sulfamethoxazole and trimethoprim Double Strength tablets (white, scored, oblong), containing 800 mg sulfamethoxazole and 160 mg trimethoprim-bottles of 100 (NDC 61971-120-01) and 500 (NDC 61971-120-05).
Imprint on tablets: VP 120.
Sulfamethoxazole and trimethoprim tablets (white, scored, round), containing 400 mg sulfamethoxazole and 80 mg trimethoprim-bottles of 100 (NDC 61971-115-01) and 500 (NDC 61971-115-05).
Imprint on tablets: VISTA over 115.
TABLETS SHOULD BE STORED AT 20° TO 25° C (68° to 77°F) ) [see USP Controlled Room Temperature] R .
DISPENSE IN TIGHT, LIGHT RESISTANT CONTAINER R .

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

What is in it

Sulfamethoxazole and Trimethoprim is a synthetic antibacterial combination product available in 800 mg sulfamethoxazole and 160 mg trimethoprim Double Strength tablets and 400 mg sulfamethoxazole and 80 mg trimethoprim tablets for oral administration.
Each Double Strength tablet contains 800 mg sulfamethoxazole and 160 mg trimethoprim plus magnesium stearate, pregelatinized starch and sodium starch glycolate.
Each tablet contains 400 mg sulfamethoxazole and 80 mg trimethoprim plus magnesium stearate, pregelatinized starch, and sodium starch glycolate.
Trimethoprim is 2, 4-diamino-5-(3,4,5 trimethoxybenzyl) pyrimidine:
the molecular formula is C 14 H 18 N 4 O 3 .
It is a white to light yellow, odorless, bitter compound with a molecular weight of 290.3 and the following structural formula:
Sulfamethoxazole is N 1 -(5-methyl-3-isoxazolyl) sulfanilamide; the molecular formula is C 10 H 11 N 3 O 3 S.
It is almost white, odorless, tasteless compound with a molecular weight of 253.28 and the following structural formula:
chemical structure chemical 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.

The stored label for this product has no list of inactive ingredients. The list on the pack is the one to check.

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 (36)

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Canada1 matching products

SULFATRIM DS 800 mg + 160 mg · tablet

Every strength and form (10)

Details

Made by	Vista Pharmaceuticals, Inc.
Active substance	Sulfamethoxazole and Trimethoprim
Used in	Antibiotics, antivirals and antifungals taken into the body
Strength	800 mg + 160 mg
Form	Tablet
Route	Oral
Packs	100 TABLET in 1 BOTTLE · 500 TABLET in 1 BOTTLE
NDC	61971-120

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

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

Tablet45 products
- 400 mg + 80 mg12
  400 mg + 80 mg · 12 companies
  +4 more
- 800 mg + 160 mg33
  800 mg + 160 mg · 33 companies
  +25 more
Suspension12 products
- 200 mg/5mL + 40 mg/5mL10
  200 mg/5mL + 40 mg/5mL · 10 companies
  +2 more
- 800 mg/20mL + 160 mg/20mL2
  800 mg/20mL + 160 mg/20mL · 2 companies
  - Chartwell Governmental & Specialty RX, LLC.
  - Chartwell RX, LLC
Injection, Solution, Concentrate2 products
- 80 mg/mL + 16 mg/mL2
  80 mg/mL + 16 mg/mL · 2 companies
  - Somerset Therapeutics, LLC
  - Teva Parenteral Medicines, Inc.

Same active substance

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See every product with Sulfamethoxazole and Trimethoprim