Rifampin

Antibiotic for Rhodococcus equi pneumonia in foals (with azithromycin/clarithromycin); MRSA and intracellular bacterial infections. Rifamycin antibiotic (rifampin/rifampicin). Mechanism: inhibits bacterial DNA-dependent RNA polymerase beta-subunit → blocks transcription and mRNA synthesis (bactericidal). Excellent intracellular penetration against Rhodococcus equi. Rapid resistance development if used as monotherapy — always combine with azithromycin or clarithromycin. Potent CYP450 inducer (many drug interactions). Key information Turns urine/tears/sweat orange-red — warn clients (stains contact lenses). Potent CYP450 inducer — numerous drug interactions. Use ALWAYS in combination (resistance develops rapidly with monotherapy). Monitor hepatic function. Foals: used with azithromycin or clarithromycin for Rhodococcus equi.

Oral capsules or tablets: Administer orally. May be given with food to improve compliance and reduce GI upset. Administer with food to reduce GI adverse effects. to reduce GI upset. Administer at consistent times. ALWAYS use in combination with another antibiotic (azithromycin or clarithromycin for Rhodococcus equi). Warn owners about orange-red discoloration of body fluids. Store at room temperature; protect from light. If a dose is missed Administer as soon as you remember. If it is almost time for the next scheduled dose, skip the missed dose and resume the normal schedule. Never double up doses to make up for a missed one. Always use in combination with another antibiotic — never give rifampin alone. Complete the full course.

Hepatotoxicity (most serious — elevated liver enzymes, potentially fatal; monitor LFTs biweekly during treatment). Orange-red discoloration of tears, urine, sweat, secretions (expected; stains soft contact lenses). GI: vomiting, anorexia, diarrhea. CNS: headache, ataxia (rare). Numerous drug interactions (potent CYP450 inducer). Resistance develops rapidly with monotherapy.

For animals ALWAYS use in combination therapy for Rhodococcus equi — rapid resistance develops as monotherapy. Monitor liver enzymes with prolonged use. — monitor liver enzymes biweekly; potentially fatal hepatotoxicity. Potent CYP450 inducer — significantly reduces plasma levels of many concurrent drugs (cyclosporine, metronidazole, azole antifungals, benzodiazepines). Orange-red body secretion discoloration is expected (inform owners). For people handling this medication Wear gloves when handling. Wash hands thoroughly with soap and water after handling. Potent antibiotic — orange-red discoloration of tears, urine, sweat, and saliva (warn handlers — stains contact lenses, clothing). Keep out of reach of children. Pregnant women and women of childbearing age should avoid contact. Teratogenic in animals. Wear gloves. Numerous drug interactions — inform your doctor.

Contact your veterinarian immediately. Rifampin overdose causes liver toxicity. Urine/tears/sweat may turn orange-red (harmless). Liver enzyme monitoring required. Supportive care.