Please check your internet connection and try again.
# Metrogyl (Metronidazole)
## Overview
Metronidazole is an antibiotic and antiprotozoal agent effective against anaerobic bacteria and certain protozoa.
## Primary Indications
* **Bacterial Vaginosis:** Treatment of bacterial vaginosis.
* **Trichomoniasis:** Treatment of urogenital trichomoniasis.
* **Amebiasis:** Treatment of amebiasis, including amebic dysentery and amebic liver abscess.
* **Giardiasis:** Treatment of giardiasis.
* **Anaerobic Bacterial Infections:** Treatment of serious anaerobic bacterial infections, such as intra-abdominal infections, skin and soft tissue infections, gynecologic infections, bone and joint infections, CNS infections, lower respiratory tract infections, and endocarditis. It is often used in combination with other antibiotics.
* **Clostridium difficile Infection (CDI):** Treatment of mild to moderate CDI.
* **Prophylaxis:** Surgical prophylaxis in specific procedures (e.g., colorectal surgery).
* **Rosacea:** Topical treatment of inflammatory papules and pustules of rosacea.
## Adult Dosing
* **Bacterial Vaginosis:**
* 500 mg orally twice daily for 7 days.
* OR 2 g orally as a single dose.
* Vaginal gel 0.75% (5g applicatorful inserted intravaginally once daily for 5 days).
* **Trichomoniasis:**
* 2 g orally as a single dose.
* OR 250 mg orally three times daily for 7 days.
* OR 375 mg orally twice daily for 7 days.
* **Amebiasis:**
* **Intestinal amebiasis:** 500-675 mg orally three times daily for 5-10 days.
* **Amebic liver abscess:** 500-750 mg orally three times daily for 5-10 days.
* **Giardiasis:** 250 mg orally three times daily for 5-7 days.
* **Anaerobic Bacterial Infections:**
* 500 mg intravenously or orally every 8 hours.
* Duration varies with infection severity, typically 7-14 days.
* Maximum dose: 4 g per day.
* **Clostridium difficile Infection (CDI):**
* Mild-to-moderate: 500 mg orally three times daily for 10-14 days.
* *Note: Vancomycin is generally preferred for initial episodes of severe or complicated CDI, and fidaxomicin is an alternative.*
* **Surgical Prophylaxis:** 1 g orally or intravenously 1 hour before surgery.
## Pediatric Dosing
Dosing in children is often weight-based and depends on the indication and severity. Specific protocols should be consulted.
* **Amebiasis/Giardiasis:**
* 35-50 mg/kg/day orally divided into three doses for 5-10 days.
* Maximum dose generally 750 mg per dose or 4 g per day.
* **Anaerobic Bacterial Infections:**
* 15-30 mg/kg/day intravenously or orally divided into three doses.
* Maximum dose generally 750 mg per dose or 4 g per day.
* **Bacterial Vaginosis:** Not typically used in pediatric patients.
* **Trichomoniasis:** Not typically used in pediatric patients.
## Dose Adjustments
* **Renal Impairment:** Dose adjustment is generally not necessary in patients with mild to moderate renal impairment. In severe renal impairment, accumulation may occur, and dose reduction may be considered, especially with prolonged therapy.
* **Hepatic Impairment:** In severe hepatic impairment, the dose should be reduced, particularly for high doses or prolonged therapy. The manufacturer recommends reducing the dose by one-third to one-half.
## Contraindications
* Hypersensitivity to metronidazole or other nitroimidazole derivatives.
* Concurrent use with disulfiram.
* Concurrent use with alcohol (disulfiram-like reaction).
## Adverse Effects
* **Common:** Nausea, vomiting, diarrhea, abdominal discomfort, metallic taste, headache, dizziness.
* **Serious:** Peripheral neuropathy (especially with prolonged use), seizures, encephalopathy, aseptic meningitis, Stevens-Johnson syndrome, toxic epidermal necrolysis, leukopenia, thrombocytopenia, pancreatitis, severe allergic reactions.
* **Disulfiram-like reaction with alcohol:** Flushing, nausea, vomiting, tachycardia, dyspnea.
## Key Drug Interactions
* **Alcohol:** Disulfiram-like reaction. Avoid alcohol during treatment and for at least 3 days after.
* **Disulfiram:** Potential for psychotic reactions. Avoid coadministration.
* **Warfarin:** Increased 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.
* **5-Fluorouracil (5-FU):** May increase toxicity of 5-FU.
## Monitoring
* Monitor for signs and symptoms of peripheral neuropathy (numbness, tingling, pain).
* Monitor for signs of central nervous system effects (seizures, encephalopathy).
* Monitor for hypersensitivity reactions.
* Monitor CBC if prolonged therapy or high doses are used.
* Monitor INR if co-administered with warfarin.
* Monitor lithium levels if co-administered with lithium.
## Clinical Pearls
* Advise patients to avoid alcohol during treatment and for at least 3 days after to prevent a disulfiram-like reaction.
* The metallic taste is common and usually transient.
* Urine may turn reddish-brown; this is harmless.
* Metronidazole can interfere with some laboratory tests, such as serum creatinine.
**Disclaimer:** This information is intended for healthcare professionals. Always verify current prescribing information and consult with relevant guidelines or specialists for patient-specific management.
