Drug Cards: Sulfonamides

Sulfonamides Overview

• Class of drugs used primarily to treat infections and inflammatory conditions.
• Effective against specific susceptible microorganisms.

Sulfadiazine (Microsulfon)

• Treats urinary tract infections, chancroid, acute otitis media, and certain types of meningitis.
• Contraindicated in patients with sulfonamide sensitivity, during lactation, and in children under 2.
• Therapeutic blood serum level: 8-12 mg%.
• Common side effects: hematologic changes, Stevens-Johnson syndrome, nausea, vomiting, headaches, and crystalluria.
• Dosage: Loading 2-4g orally; maintenance 2-4g/day in divided doses.
• Caution with renal or hepatic impairment, and bronchial asthma; administer 1 hour before or 2 hours after meals.

Sulfasalazine (Azulfidine, Azulfidine EN-tabs)

• Primarily used for ulcerative colitis and rheumatoid arthritis.
• Contraindications include intestinal obstruction, porphyria, and hypersensitivity.
• Therapeutic blood serum level: 1-4 g/day in divided doses.
• Side effects similar to sulfadiazine; can cause orange-yellow urine and skin.
• Dosage: 2 g/day orally in evenly spaced doses.
• Take with food or after meals with a full glass of water; warn about potential discoloration.

Sulfisoxazole (Gantrisin, Gantrisin Pediatric, Truxazole)

• Used for the same indications as sulfadiazine.
• Contraindications: liver problems, kidney disease, and certain anemias.
• Therapeutic blood serum level: 50-150 μg/ml.
• Side effects consistent with other sulfonamides.
• Dosage: 4-8 g/day orally in divided doses.
• Advise to take with full glass of water; tablets may be crushed or chewed.

Trimethoprim/Sulfamethoxazole (Bactrim, Bactrim DS, Septra, Septra DS)

• Indicated for urinary tract infections, acute otitis media, and traveler's diarrhea.
• Contraindications: late-term pregnancy, nursing mothers, and folate deficiency anemia.
• Therapeutic blood serum level: 160 mg TMP/800 mg SMZ administered every 12 hours.
• Side effects: gastrointestinal disturbances, allergic reactions, hematologic changes, and Stevens-Johnson syndrome.
• Dosage: 8-10 mg/kg/day IV in divided doses.
• Not recommended for group A beta-hemolytic strep and certain high-risk patients; caution with sun exposure to prevent reactions.

Mafenide (Sulfamylon)

• Used for managing second- and third-degree burns.
• Important for reducing infection and promoting healing in damaged skin.
• Requires monitoring for side effects and appropriate application methods.