Yes: Tablet

Antibiotic, Sulfonamide Derivative

Treatment of urinary tract infections, nocardiosis, toxoplasmosis, acute otitis media, and acute exacerbations of chronic bronchitis due to susceptible organisms

B/D (at term)

Porphyria, hypersensitivity to any sulfa drug or any component, pregnancy during 3rd trimester, children <2 months of age unless indicated for the treatment of congenital toxoplasmosis, sunscreens containing PABA

Maintain adequate fluid intake to prevent crystalluria; use with caution in patients with renal or hepatic impairment, and patients with G-6-PD deficiency; should not be used for group A beta-hemolytic streptococcal infections

>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%: Vasculitis, thyroid function disturbance, crystalluria, jaundice, hematuria, acute nephropathy, interstitial nephritis, serum sickness-like reactions

Symptoms of overdose include drowsiness, dizziness, anorexia, abdominal pain, nausea, vomiting, hemolytic anemia, acidosis, jaundice, fever, agranulocytosis; 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 (ie, procaine, proparacaine, tetracaine); cyclosporine levels may be decreased

Increased effect/toxicity of oral anticoagulants, oral hypoglycemic agents, hydantoins, uricosuric agents, methotrexate when administered with sulfonamides

Increased toxicity of sulfonamides with diuretics, indomethacin, methenamine, probenecid, and salicylates

Protect from light

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

Absorption: Oral: 90%

Distribution: Crosses the placenta; readily enters the CSF

Protein binding: 70%

Metabolism: Primarily in the liver, with 10% to 20% as the N-acetylated form in the plasma

Half-life: 9-12 hours, prolonged with renal impairment

Time to peak serum concentration: Within 3-4 hours

Elimination: Unchanged drug (20%) and its metabolites are excreted in urine

Oral:

Adults: Initial: 2 g, then 1 g 2-3 times/day; maximum: 3 g/24 hours

Dosing adjustment/interval in renal impairment:

Cl_cr 10-50 mL/minute: Administer every 12-24 hours

Cl_cr <10 mL/minute: Administer every 24 hours

Hemodialysis: Moderately dialyzable (20% to 50%)

Should be administered 1 hour before or 2 hours after a meal on an empty stomach; avoid large quantities of vitamin C or acidifying agents (cranberry juice) to prevent crystalluria; presence of food delays but does not reduce absorption

Monitor urine output

May interfere with Jaffé alkaline picrate reaction assay for creatinine resulting in over-estimations of ~10% in the range of normal values; decreased effect with PABA or PABA metabolites of drugs (ie, procaine, proparacaine, tetracaine)

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 leukopenia; 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 a full glass of water. Take full course of therapy even if you 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 sunscreen, 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, blackened stool, or difficulty breathing. Pregnancy precautions: Inform prescriber if you are pregnant.

Maintain adequate hydration

Suspension, oral (cherry flavor): 500 mg/5 mL (480 mL)

Tablet: 500 mg

Ljungberg B and Nilsson-Ehle I, "Pharmacokinetics of Antimicrobial Agents in the Elderly," Rev Infect Dis, 1987, 9(2):250-64.

Varoquaux O, Lajoie D, Gobert C, et al, "Pharmacokinetics of the Trimethoprim-Sulfamethoxazole Combination in the Elderly," Br J Clin Pharmacol, 1985, 20:575-81.