SULFATRIM

INDICATIONS AND USAGE To reduce the development of drug-resistant bacteria and maintain the effectiveness of sulfamethoxazole and trimethoprim oral suspension and other antibacterial drugs, sulfamethoxazole and trimethoprim oral suspension should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. 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 empiric selection of therapy. Urinary Tract Infections 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 Streptococcus 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. Travelers' Diarrhea in Adults For the treatment of travelers' diarrhea due to susceptible strains of enterotoxigenic E. coli .

DOSAGE AND ADMINISTRATION 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 The usual adult dosage in the treatment of urinary tract infections is four teaspoonfuls (20mL) 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: Weight Dose - every 12 hours Teaspoonfuls lb kg 22 10 1 (5 mL) 44 20 2 (10 mL) 66 30 3 (15 mL) 88 40 4 (20 mL) For Patients with Impaired Renal Function When renal function is impaired, a reduced dosage should be employed using the following table: Creatinine Clearance (mL/min) Recommended Dosage Regimen Above 30 Use standard regimen 15 to 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 four teaspoonfuls (20 mL) sulfamethoxazole and trimethoprim oral suspension every 12 hours for 14 days. Pneumocystis Carinii Pneumonia Treatment Adults and Children: The recommended dosage for treatment of 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 days. 10 The following table is as a guideline for the upper limit of this dosage: Weight Dose - every 6 hours Teaspoonfuls lb kg 18 8 1 (5 mL) 35 16 2 (10 mL) 53 24 3 (15 mL) 70 32 4 (20 mL) 88 40 5 (25 mL) 106 48 6 (30 mL) 141 64 8 (40 mL) 176 80 10 (50 mL) 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 oral suspension daily. 11 For children, 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. 12 The following table is a guideline for the attainment of this dosage in children: Body Surface Area Dose every 12 hours (m 2 ) Teaspoonfuls 0.26 1 / 2 (2.5 mL) 0.53 1 (5 mL) 1.06 2 (10 mL) Travelers' Diarrhea in Adults For the treatment of travelers' diarrhea, the usual adult dosage is four teaspoonfuls (20 mL) of sulfamethoxazole and trimethoprim oral suspension every 12 hours for 5 days.

CONTRAINDICATIONS Sulfamethoxazole and trimethoprim is contraindicated in patients with a known hypersensitivity to trimethoprim or sulfonamides, in patients with a history of drug-induced immune thrombocytopenia with use of trimethoprim and/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 oral suspension 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.

ADVERSE REACTIONS The most common adverse reactions are gastrointestinal disturbances (nausea, vomiting, anorexia) and allergic skin reactions (such as rash and urticaria). Fatalities and serious adverse reactions, including severe cutaneous adverse reactions (SCARs), including Stevens-Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms (DRESS), acute febrile neutrophilic dermatosis (AFND), acute generalized erythematous pustulosis (AGEP); fulminant hepatic necrosis; agranulocytosis, aplastic anemia and other blood dyscrasias; acute and delayed lung injury; anaphylaxis and circulatory shock have occurred with the administration of sulfamethoxazole and trimethoprim products, (see WARNINGS ). Hematologic Agranulocytosis, aplastic anemia, thrombocytopenia, leukopenia, neutropenia, hemolytic anemia, megaloblastic anemia, hypoprothrombinemia, methemoglobinemia, eosinophilia. Allergic/Immune Reactions Stevens-Johnson syndrome, toxic epidermal necrolysis, anaphylaxis, allergic myocarditis, erythema multiforme, exfoliative dermatitis, angioedema, drug fever, chills, Henoch-Schönlein purpura, serum sickness-like syndrome, generalized allergic reactions, generalized skin eruptions, photosensitivity, conjunctival and scleral injection, pruritus, urticaria and rash, periarteritis nodosa, hemophagocytic lymphohistiocytosis (HLH), systemic lupus erythematosus, drug reaction with eosinophilia and systemic symptoms (DRESS), acute generalized erythematous pustulosis (AGEP), and acute febrile neutrophilic dermatosis (AFND) (see WARNINGS ). 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, pulmonary infiltrates, acute eosinophilic pneumonia, acute and delayed lung injury, interstitial lung disease, acute respiratory failure (see WARNINGS ). Cardiovascular Circulatory shock (see WARNINGS ), QT prolongation resulting in ventricular tachycardia and torsades de pointes . 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

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 coadministration 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 also 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 sulfamethoxazole/trimethoprim and an angiotensin converting enzyme inhibitor. 7,8

DESCRIPTION Sulfamethoxazole and trimethoprim is a synthetic antibacterial combination product containing 200 mg sulfamethoxazole and 40 mg trimethoprim per 5 mL for oral administration. Sulfamethoxazole is N 1 -(5-methyl-3-isoxazolyl) sulfanilamide; the molecular formula is C 10 H 11 N 3 O 3 S. It is an almost white, odorless, tasteless compound with a molecular weight of 253.28 and the following structural formula is: 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 it has the following structural formula is: Chemical Structure Chemical Structure INACTIVE INGREDIENTS: alcohol (less than 0.5%), carboxymethylcellulose sodium, citric acid, FD&C Red #40, FD&C Yellow #6, cherry flavor, methylparaben, microcrystalline cellulose and carboxymethylcellulose sodium, polysorbate 80, propylene glycol, propylparaben, purified water, saccharin sodium, simethicone emulsion, sucrose.

OVERDOSAGE 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.

HOW SUPPLIED Sulfamethoxazole and Trimethoprim Oral Suspension USP, containing 200 mg sulfamethoxazole and 40 mg trimethoprim per teaspoonful (5 mL), is a cherry flavored suspension available in: NDC 68788-7345-4: 16 fl oz (473 mL) bottle Store at 20°-25°C (68°-77°F) [see USP Controlled Room Temperature]. Protect from light. SHAKE WELL BEFORE USING. Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure (as required). To report SUSPECTED ADVERSE REACTIONS, contact Pharmaceutical Associates, Inc. at 1-800-845-8210 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. Rx only