Metronidazole
Generic Details
Generic Name
Metronidazole
Other Names
- Flagyl
- MetroGel
- MetroCream
- Noritate
- Vandazole
Drug Class
- Antibacterial
- Antiprotozoal
Chemical Formula
C₆H₉N₃O₃
Molecular Weight
171.15 g/mol
Mechanism of Action
- Disruption of DNA synthesis in susceptible organisms
Indications
- Bacterial infections
- Protozoal infections
- Helicobacter pylori eradication in peptic ulcer disease
Common Dosage Forms
- Tablet
- Capsule
- Topical gel
- Topical cream
Typical Dosage
- 500 mg orally every 8 hours for 7 days for most infections
Pediatric Dosage
- 7.5 mg/kg/dose (maximum 500 mg) every 12 hours for 10 days
Geriatric Dosage
- Dose adjustments may be needed based on renal function
Side Effects
- Nausea
- Metallic taste
- Dizziness
- Headache
- Peripheral neuropathy
- Disulfiram-like reaction with alcohol
Contraindications
- Hypersensitivity to metronidazole or other nitroimidazole derivatives
- First trimester of pregnancy
Pregnancy Category
- Category B - Animal reproduction studies have failed to demonstrate a risk to the fetus
Lactation Safety
- Considered compatible with breastfeeding
Drug Interactions
- Warfarin (increases INR)
- Alcohol (disulfiram-like reaction)
- Lithium (increases lithium levels)
Overdose Symptoms
- Seizures
- Encephalopathy
- Peripheral neuropathy
Antidote for Overdose
- No specific antidote; manage symptoms and provide supportive care
Storage Conditions
- Store at room temperature away from moisture and heat
Pharmacokinetics
- Absorption: Rapid and almost complete
- Distribution: Penetrates most tissues including CNS and crosses the placenta
- Metabolism: In the liver via oxidation and glucuronidation
- Excretion: Mainly via urine (60-80%) as metabolites
Precautions
- Avoid alcohol consumption during and for 3 days after discontinuing metronidazole
Warnings
- May interact with alcohol leading to a disulfiram-like reaction
Others
- Metronidazole can also be used in the treatment of periodontal disease and other oral infections.