Metrogyl%2525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520%2525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252528metronidazole%2525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252529

# Metronidazole ## Overview Metronidazole is an antibiotic and antiprotozoal agent effective against anaerobic bacteria and certain parasites. It is available in oral, intravenous, and topical formulations. The provided drug name "Metrogyl%2525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520%2525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252528metronidazole%2525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252529 appears to be a brand name for metronidazole. ## Primary Indications * **Bacterial infections:** Intra-abdominal infections, skin and soft tissue infections, gynecologic infections, bone and joint infections, central nervous system infections, lower respiratory tract infections, endocarditis, and C. difficile-associated diarrhea (CDAD). * **Protozoal infections:** Trichomoniasis, amebiasis, giardiasis. * **Surgical prophylaxis:** Particularly for colorectal surgery. * **Topical use:** Rosacea and bacterial vaginosis. ## Adult Dosing * **Bacterial infections:** * Oral: 500 mg every 8 hours. * IV: 15 mg/kg loading dose, then 7.5 mg/kg every 6-8 hours. Maximum daily dose is generally 4 grams. * Duration varies based on infection severity, typically 7-14 days. * **C. difficile-associated diarrhea (CDAD):** * Oral: 500 mg every 8 hours for 10-14 days. Vancomycin is often preferred for initial episodes and is the standard for severe cases. * **Trichomoniasis:** * Oral: Single dose of 2 grams, or 250 mg every 8 hours for 7 days, or 500 mg every 12 hours for 7 days. * **Amebiasis:** * Oral: 500-750 mg every 8 hours for 7-10 days. * **Giardiasis:** * Oral: 250 mg every 8 hours for 5-7 days, or a single dose of 2 grams. * **Surgical prophylaxis:** * Oral/IV: 500 mg to 1 gram given 4 hours before surgery, followed by 500 mg every 8 hours for up to 24 hours post-operatively. ## Pediatric Dosing * Dosing is weight-based and depends on the indication. Consult specific pediatric guidelines. * **Bacterial infections:** * Oral/IV: 30-40 mg/kg/day divided into 3 doses. Maximum daily dose typically 4 grams. * **Amebiasis:** * Oral: 35-50 mg/kg/day divided into 3 doses for 7-10 days. * **Giardiasis:** * Oral: 15 mg/kg/day divided into 3 doses for 5-7 days. ## Dose Adjustments * **Hepatic impairment:** Use with caution. Consider reducing the dose by 25-50% in severe hepatic dysfunction. * **Renal impairment:** Dose adjustment is generally not required for hemodialysis or peritoneal dialysis patients, as metronidazole is effectively removed. ## Contraindications * Hypersensitivity to metronidazole or other nitroimidazole derivatives. * First trimester of pregnancy (though benefits may outweigh risks in specific situations). * Concurrent use with disulfiram or alcohol (due to disulfiram-like reaction). ## Adverse Effects * **Common:** Nausea, vomiting, diarrhea, abdominal pain, metallic taste, headache, dizziness. * **Serious:** Peripheral neuropathy (especially with prolonged use), central nervous system effects (seizures, encephalopathy), Stevens-Johnson syndrome, aplastic anemia, pancreatitis, thrombophlebitis (with IV administration), opportunistic infections (e.g., Candida). * **Disulfiram-like reaction:** Flushing, vomiting, tachycardia when taken with alcohol. ## Key Drug Interactions * **Alcohol:** Disulfiram-like reaction. Avoid alcohol during and for at least 72 hours after treatment. * **Warfarin:** Potentiates anticoagulant effect. Monitor INR closely and adjust warfarin dose as needed. * **Lithium:** May increase lithium levels, leading to toxicity. Monitor lithium levels. * **Phenytoin, Phenobarbital:** May decrease metronidazole levels. * **Cyclosporine:** May increase cyclosporine levels. Monitor cyclosporine levels. * **Disulfiram:** Concurrent use is contraindicated. * **5-Fluorouracil (5-FU):** May increase toxicity of 5-FU. ## Monitoring * Monitor for signs and symptoms of infection resolution. * Monitor for adverse effects, particularly neuropathy and CNS effects, especially with prolonged therapy. * Monitor INR if used concurrently with warfarin. * Monitor lithium levels if used concurrently with lithium. ## Clinical Pearls * Metronidazole has a metallic taste, which can be a significant patient complaint. * Advise patients to avoid alcohol during and for at least 72 hours after treatment to prevent a disulfiram-like reaction. * Urine may turn a reddish-brown color; this is harmless. * IV formulation should be administered slowly to minimize thrombophlebitis. *** *This information is intended for healthcare professionals. It is essential to consult the most current prescribing information and relevant clinical guidelines for complete details. Always verify current drug information before making clinical decisions.*