Yes

Antibiotic, Sulfonamide Derivative

Treatment of urinary tract infections and nocardiosis, rheumatic fever prophylaxis; adjunctive treatment in toxoplasmosis; uncomplicated attack of malaria

B/D (at term)

Porphyria, hypersensitivity to any sulfa drug or any component, pregnancy at term, children <2 months of age unless indicated for the treatment of congenital toxoplasmosis, sunscreens containing PABA, nursing mothers

Use with caution in patients with impaired hepatic function or impaired renal function, G-6-PD deficiency; dosage modification required in patients with renal impairment; fluid intake should be maintained greater than or equal to 1500 mL/day, or administer sodium bicarbonate to keep urine alkaline; more likely to cause crystalluria because it is less soluble than other sulfonamides

>10%:

Central nervous system: Fever, dizziness, headache

Dermatologic: Itching, rash, photosensitivity

Gastrointestinal: Anorexia, nausea, vomiting, diarrhea

1% to 10%:

Dermatologic: Lyell's syndrome, Stevens-Johnson syndrome

Hematologic: Granulocytopenia, leukopenia, thrombocytopenia, aplastic anemia, hemolytic anemia

Hepatic: Hepatitis

<1%: Thyroid function disturbance, crystalluria, jaundice, interstitial nephritis, acute nephropathy, hematuria, serum sickness-like reactions

Symptoms of overdose include drowsiness, dizziness, anorexia, abdominal pain, nausea, vomiting, hemolytic anemia, acidosis, jaundice, fever, agranulocytosis; doses of as little as 2-5 g/day may produce toxicity; the aniline radical is responsible for hematologic toxicity

High volume diuresis may aid in elimination and prevention of renal failure

Decreased effect with PABA or PABA metabolites of drugs (eg, procaine, proparacaine, tetracaine, sunscreens); increased effect of oral anticoagulants and oral hypoglycemic agents

Tablets may be crushed to prepare oral suspension of the drug in water or with a sucrose-containing solution; aqueous suspension with concentrations of 100 mg/mL should be stored in the refrigerator and used within 7 days

Interferes with bacterial growth by inhibiting bacterial folic acid synthesis through competitive antagonism of PABA

Absorption: Oral: Well absorbed

Distribution: Throughout body tissues and fluids including pleural, peritoneal, synovial, and ocular fluids; distributed throughout total body water; readily diffused into CSF; appears in breast milk

Metabolism: By N-acetylation

Half-life: 10 hours

Elimination: In urine as metabolites (15% to 40%) and as unchanged drug (43% to 60%)

Oral:

Newborns and Children <2 months: 100 mg/kg/day divided every 6 hours in conjunction with pyrimethamine 1 mg/kg/day once daily and supplemental folinic acid 5 mg every 3 days for 6 months

Children >2 months: 25-50 mg/kg/dose 4 times/day

Toxoplasmosis:

Children >2 months: Loading dose: 75 mg/kg; maintenance dose: 120-150 mg/kg/day, maximum dose: 6 g/day; divided every 4-6 hours in conjunction with pyrimethamine 2 mg/kg/day divided every 12 hours for 3 days followed by 1 mg/kg/day once daily (maximum: 25 mg/day) with supplemental folinic acid

Adults: 2-4 g/day divided every 4-8 hours in conjunction with pyrimethamine 25 mg/day and with supplemental folinic acid

Prevention of recurrent attacks of rheumatic fever:

>30 kg: 1 g/day

<30 kg: 0.5 g/day

Supplemental folinic acid should be administered to reverse symptoms or prevent problems due to folic acid deficiency. Avoid large quantities of vitamin C or acidifying agents (cranberry juice) to prevent crystalluria.

Dizziness is common; sulfonamides reported to cause restlessness, irritability, depression, euphoria, disorientation, panic, hallucinations, and delusions

Photosensitivity is common; use caution with concurrent psychotropics; may cause granulocytopenia; caution with clozapine and carbamazepine

No information available to require special precautions

No effects or complications reported

Take as directed, at regular intervals around-the-clock. Take 1 hour before or 2 hours after meals with full glass of water. Complete full course of therapy even if you are feeling better. Avoid aspirin or aspirin-containing products and avoid large quantities of vitamin C. It is very important to maintain adequate hydration (2-3 L/day of fluids unless instructed to restrict fluid intake) to prevent kidney damage. You may experience dizziness or headache (use caution when driving or engaging in tasks requiring alertness until response to drug is known); photosensitivity (use sunblock, wear protective clothing and eyewear, and avoid direct sunlight); nausea, vomiting, or loss of appetite (small frequent meals, frequent mouth care, sucking lozenges, or chewing gum may help). Report skin rash, persistent diarrhea, persistent or severe sore throat, fever, vaginal itching or discharge, unusual bruising or bleeding, fatigue, persistent headache or abdominal pain, or difficulty breathing. Pregnancy/breast-feeding precautions: Inform prescriber if you are pregnant. Do not breast-feed.

Maintain adequate hydration and monitor urine output

Tablet: 500 mg

Frenkel JK, "Toxoplasmosis," Pediatr Clin North Am, 1985, 32(4):917-32.

Katlama C, De Wit S, O'Doherty E, et al, "Pyrimethamine-Clindamycin vs Pyrimethamine-Sulfadiazine as Acute and Long-Term Therapy for Toxoplasmic Encephalitis in Patients With AIDS," Clin Infect Dis, 1996, 22(2):268-75.

Porter SB and Sande MA, "Toxoplasmosis of the Central Nervous System in the Acquired Immunodeficiency Syndrome," N Engl J Med, 1992, 327(23):1643-8.

Torre D, Casari S, Speranza F, et al, "Randomized Trial of Trimethoprim-Sulfamethoxazole Versus Pyrimethamine-Sulfadiazine for Therapy of Toxoplasmic Encephalitis in Patients With AIDS. Italian Collaborative Study Group," Antimicrob Agents Chemother, 1998, 42(6):1346-9.