Sulfamethoxazole and Trimethoprim Suspension

For all patients taking sulfamethoxazole and trimethoprim suspension:

• If you have an allergy to sulfamethoxazole, trimethoprim, or any other part of this medicine.
• If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
• If you have anemia caused by a lack of folic acid.
• If you have any of these health problems: Kidney disease or liver disease.
• If you have asthma.
• If you have thyroid disease.
• If you have porphyria.
• If you have ever had a low platelet count when using trimethoprim or a sulfa (sulfonamide) drug.
• If you are taking any of these drugs: Amantadine, cyclosporine, dofetilide, indomethacin, leucovorin, methotrexate, or pyrimethamine.
• If you are taking or have recently taken any of these drugs: Benazepril, captopril, enalapril, fosinopril, lisinopril, moexipril, perindopril, quinapril, ramipril, or trandolapril.
• If you are taking a water pill.
• If you are breast-feeding. Do not breast-feed while you take sulfamethoxazole and trimethoprim suspension.

Children:

• If your child is younger than 2 months of age. Do not give this medicine to an infant younger than 2 months of age.

This is not a list of all drugs or health problems that interact with sulfamethoxazole and trimethoprim suspension.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

Sulfamethoxazole and trimethoprim oral suspension, USP is a synthetic antibacterial combination product containing 200 mg sulfamethoxazole and 40 mg trimethoprim in each teaspoonful (5 mL).

Sulfamethoxazole is N1-(5-methyl-3-isoxazolyl)sulfanilamide; the molecular formula is C10H11N3O3S. It is a white to off-white, practically odorless, crystalline powder, tasteless compound with a molecular weight of 253.28 and the following structural formula:

Trimethoprim is 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine; the molecular formula is C14H18N4O3. It is a white or cream-colored crystals or crystalline powder with a molecular weight of 290.3 and the following structural formula:

Each teaspoonful (5 mL) of the oral suspension contains 200 mg sulfamethoxazole and 40 mg trimethoprim as well as the following inactive ingredients: alcohol 0.04% (v/v), carboxymethylcellulose sodium, citric acid anhydrous, colloidal silicon dioxide, FD&C Red #40, flavour cherry #557, glycerin, methyl paraben, microcrystalline cellulose and carboxymethylcellulose sodium, polysorbate 80, purified water, saccharin sodium, sodium benzoate, and sorbitol solution.

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, hyponatremia  (see PRECAUTIONS: Electrolyte Abnormalities).   

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 pulmonary infiltrates (see WARNINGS).

Miscellaneous

Weakness, fatigue, insomnia.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of trimethoprim-sulfamethoxazole. Because these reactions were reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency or establish a causal relationship to drug exposure: 

• Thrombotic thrombocytopenia purpura
• Idiopathic thrombocytopenic purpura
• QT prolongation resulting in ventricular tachycardia and torsade de pointes

Sulfamethoxazole and trimethoprim oral suspension is contraindicated 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

Adults

The usual adult dosage in the treatment of urinary tract infections is four teaspoonfuls (20 mL) sulfamethoxazole and trimethoprim oral suspension every 12 hours for 10 to 14 days. An identical daily dosage is used for 5 days in the treatment of shigellosis.

Children

The recommended dose for children 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 2 months of age or older:

For Patients with Impaired Renal Function

When renal function is impaired, a reduced dosage should be employed using the following table:

Acute Exacerbations of Chronic Bronchitis in Adults

The usual adult dosage in the treatment of acute exacerbations of chronic bronchitis is four teaspoonfuls (20 mL) sulfamethoxazole and trimethoprim oral suspension every 12 hours for 14 days.

Pneumocystis Jiroveci  Pneumonia

Treatment

Adults and Children

The recommended dosage for treatment of patients with documented Pneumocystis  jiroveci 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 days.11 The following table is a guideline for the upper limit of this dosage:

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 four teaspoonfuls (20 mL) of the suspension daily.12


Children

For children, the recommended dose is 750 mg/m2/day sulfamethoxazole with 150 mg/m2/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.13 The following table is a guideline for the attainment of this dosage in children:

Traveler’s Diarrhea in Adults

For the treatment of traveler’s diarrhea, the usual adult dosage is four teaspoonfuls (20 mL) of the suspension every 12 hours for 5 days.

NDC 65862-496-50
Rx only 
Sulfamethoxazole and
Trimethoprim Oral Suspension, USP
200 mg/40 mg per 5 mL
AUROBINDO             50 mL