|1. TYPE OF DRUG – METRONIDAZOLE|
|Metronidazole is of the nitroimidazole class.
|2. INDICATIONS (USE) – METRONIDAZOLE|
|Metronidazole is given for treatment of protozoal infections like amoebiasis, giardiasis and trichomonas vaginitis. It is also used in the treatment of anaerobic infection, ulcerative gingivitis, trench mouth, guinea worm infestation.
|3. MECHANISM OF ACTION (MOA) – METRONIDAZOLE|
|Inhibits nucleic acid synthesis by disrupting DNA and causing strand breakage; amebicidal, bactericidal, trichomonacidal
|4. ROUTES OF ADMINISTRATION- METRONIDAZOLE|
|Metronidazole comes as a tablet and an extended release tablet to take by mouth.
Intra venous (IV) injection.
|5. ONSET OF EFFECT OR ACTION- METRONIDAZOLE|
|Within a few hours. Full benefits seen after 1-2 days.
|6. DOSAGE (DOSING INFORMATION) – METRONIDAZOLE|
|Oral:200-800 mgs three times daily.
Parenteral: 15 mg/kg infused over 1 hour, followed by 7.5 mg/kg every 6 hours.
|7. HALF LIFE (DURATION OF ACTION) – METRONIDAZOLE|
|Half-life: 25-75 hr (neonates); 8 hr (others); prolonged in patients with hepatic impairment.
|8. ADVERSE EFFECTS OR SIDE EFFECTS – METRONIDAZOLE|
|9. CONTRAINDICATIONS – METRONIDAZOLE|
|Hypersensitivity to metronidazole or other nitroimidazoles (although cautious desensitization has been applied)
Pregnancy, 1st trimester (controversial)
Use of disulfiram within past 2 weeks; use of alcohol during therapy or within 3 days of discontinuing therapy
|10. DRUG INTERACTIONS – METRONIDAZOLE|
|Acute psychoses or confusion with disulfiram. Additive/synergistic effect with other antimicrobials. Effects reduced with phenobarbital or phenytoin.
Potentially Fatal: Disulfiram-like reaction with alcohol. Increased risk of adverse effects of coumarin anticoagulants, phenytoin, lithium, ciclosporin, fluorouracil. Increased risk of neurological effects with cimetidine.
|11. EXCRETION- METRONIDAZOLE|
|Mainly via urine (as metabolites); via faeces (small amounts). Elimination half-life: 8 hours; longer in neonates and severe hepatic impairment.