Metronidazole Pharmacology


About Metronidazole
A nitroimidazole antibiotic, Anti-infective, Antiprotozoal,amebicide.
Mechanism of Action of Metronidazole
Metronidazole is nitro imidazoles which have broad spectrum cidal activity against Protozoa and some anaerobic bacteria. Its selective toxicity to anaerobic microbes involves 1. Drug enters the cell by diffusion, 2. Nitro group of drug is reduced by redox proteins present only in anaerobic organisms to reactive nitro radical which exerts cytotoxic action by damaging DNA and other critical biomolecules. 3. DNA helix destabilization & strand breakage has been observed.
Pharmacokinets of Metronidazole
Absorption: Well absorbed orally, Distribution: Widely distributed,
Metabolism: Metabolized in liver by oxidation & glucuronide conjugation, Excretion: Excreted in urine.
Onset of Action for Metronidazole
1 to 2 days
Duration of Action for Metronidazole
Half Life of Metronidazole
8 hours.
Side Effects of Metronidazole
2.Metallic taste
7.Looseness of stool.
8.Peripheral neuropathy &CNS effects.
11.Transient leucopenia
12.Dry mouth
13.Abdominal distress
16.Thrombophlebitis at site of injection
Contra-indications of Metronidazole
1.Hypersensitivity to the drug
2.Blood dyscrasias
3.CNS disorders
Special Precautions while taking Metronidazole
1.Renal impairment
2.Hepatic impairment
3.Alcoholic cirrhosis
4.Use cautiously along with other hepatotoxic drugs & In visual field changes
Pregnancy Related Information
Use with caution
First trimester:contra indicated
Old Age Related Information
May be used.
Breast Feeding Related Information
Children Related Information
Use with caution
Neonates: Contraindicated
Indications for Metronidazole
3.Trichomonas vaginitis
4.Pseudo membranous enterocolitis
5.Anaerobic bacterial infections after surgery, Brain abscess, & Endocarditis
6.Helicobacter pylori infections
7.Ulcerative gingivitis
Interactions for Metronidazole
Warfarin & other coumarin anticoagulants: Potentiates the anticoagulant effect resulting in increased prothrombin time.
Alcohol: A disulfiram-like reaction. Abdominal cramps, nausea, vomiting, headache & flushing.
Disulfiram: Acute psychotic reaction or confusional state.
Phenobarbital & Phenytoin: Increased metabolism of metronidazole resulting in decreased efficacy.
Lithium: Increased lithium levels and toxicity.
Flurouracil: Increased toxicity of flurouracil.
Lab tests: May interfere with chemical analysis for AST,SGOT, ALT, SGPT, LDH, triglycerides and hexokinase glucose. Zero values may occur.
Typical Dosage for Metronidazole
Amoebiasis:400 to 800 mg 8hourly for 5 to 10days depending up on the severity of infection
In severe infections and liver abscess: 1gm as slow I.V. infusion followed by 0.5 gm twice daily till oral therapy is started
Giardiasis:200mg 8hourly for 1week or 2gm/day for 3days or I.V.500mg thrice daily
Trichomonas vaginitis: 400mg 8 hourly for a week or 2gm once daily for a week.
Male partner should be concurrently treated with the drug
Pseudo membranous enterocolitis:800 mg 8hourly
Anaerobic bacterial infections after surgery, Brain abscess, & Endocarditis:400 to 800 mg 8hourly
In severe cases: 15mg/kg I.V. infusion for 1hour followed by 7.5mg/kg 4 times daily till oral therapy is substituted
Helicobacter pylori infections:400mg 8hourly along with amoxicillin/clarithromycin and a proton pump inhibitor
Ulcerative gingivitis:200 to 800mg 8hourly
Amoebiasis: 30 to 50mg/kg/day for 5to10 days.
Giardiasis:10 to 15mg/kg/day thrice daily
Children (below 12years): 7.5mg/kg I.V.
Schedule of Metronidazole
Storage Requirements for Metronidazole
Store in a well closed container in a cool dark place. Keep out of the reach of children.
Effects of Missed Dosage of Metronidazole
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Metronidazole
Treatment is supportive & symptomatic. Drug is removed by induced emesis, gastric lavage, and administration of activated charcoal & use of cathartics. For controlling seizures diazepam & phenytoin may be used.

Home Delivery for Metronidazole in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including metronidazole.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for metronidazole and other medicines and health products. Home delivery services for metronidazole may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take metronidazole only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for metronidazole before they complete the sale. You can get this information while placing the order for metronidazole with the pharmacy.

Metronidazole is a generic medicine name and there are several brands available for it. Some of the brands for metronidazole might be better known than metronidazole itself. If the pharmacy that's willing to deliver medicines to your home doesn't have metronidazole in stock, you can ask for one of the branded alternatives for metronidazole.