Metronidazole

Pregnancy & gynaecology-specific. Every dose row is source-referenced; verify against institutional protocols.

MetronidazoleNitroimidazole

Regimens checked: 2026-10-17. Each indication has its own preparation, limits and safety checks.

Metronidazole: indication-specific regimens
Indication	Dose	Route	Frequency	Duration / preparation	Maximum	Monitoring / cautions
Symptomatic BV, including pregnancy where treatment is indicated CDC · 2021 STI guidelinechecked	500 mg	Oral	Twice daily	7 days · One 500 mg tablet each dose. Alternative formulations/regimens must be prescribed separately CDC does not require routine alcohol abstinence on evidence of a disulfiram-like interaction; product leaflets may give different advice. Follow the dispensed product instructions and discuss the difference.	1 g/day for 7 days in this CDC regimen	Monitor Symptoms and tolerance; recurrent symptoms need reassessment, not indefinite repeat courses Contraindications / cautions Nitroimidazole allergy; review warfarin, lithium and severe hepatic disease
Trichomoniasis, including symptomatic pregnant women CDC · 2021 STI guidelinechecked	500 mg	Oral	Twice daily	7 days · One 500 mg tablet each dose; assess vomiting/adherence	1 g/day for this 7-day regimen	Monitor Treat partner(s), avoid sex until both treatment courses complete and symptoms resolve, and retest women at about 3 months Contraindications / cautions Nitroimidazole allergy; review interactions and hepatic impairment
Anaerobic cover in the complete CDC PID regimen CDC · 2021 STI guidelinechecked	500 mg	Oral	Twice daily	14 days · One 500 mg tablet twice daily, with doxycycline and the appropriate cephalosporin regimen	1 g/day for this PID regimen	Monitor Clinical response within 72 h and tolerance Contraindications / cautions Nitroimidazole allergy; review interactions and severe hepatic impairment
Combination treatment of selected septic miscarriage/endometritis or caesarean chorioamnionitis MSFchecked	500 mg	IV infusion	Every 8 hours	Review daily and switch to oral when feasible; duration is source-specific: uncomplicated infection recovery versus septic miscarriage (10–14 days in Malaysian NAG) · Ready-to-use 500 mg/100 mL (5 mg/mL) bag infused over 30 min; do not add other drugs to the bag Renal / hepatic: In severe hepatic impairment the cited MSF monograph reduces the daily dose to one third	1.5 g/day in this regimen; severe hepatic impairment requires reduction	Monitor Clinical response, LFTs in prolonged treatment, interacting anticoagulants and neuropathy with prolonged exposure Contraindications / cautions Nitroimidazole allergy; severe hepatic impairment requires a reduced regimen

Pregnancy safety

CDC permits treatment of indicated BV/trichomoniasis in pregnancy; select the syndrome-specific regimen.

Lactation

Usual divided-dose courses differ from a 2 g single dose; review the prescribed regimen and infant circumstances.

CDC · 2021 STI guidelinecheckedIN REVIEW