Sexual Health / HIV/Nitroimidazole (STI)

Metronidazole (BV / trichomonas)

also: bacterial vaginosis · trichomonas · disulfiram alcohol

Overview

Treatment of bacterial vaginosis and trichomoniasis. The alcohol (disulfiram-like) reaction is the classic counselling point.

Mechanism

Nitroimidazole — reduced intracellularly by anaerobes/protozoa to a reactive nitro radical causing DNA strand breakage → cidal against anaerobes and protozoa (Trichomonas).

Indications

Bacterial vaginosis (400 mg BD 5–7 days or 2 g stat)
Trichomonas vaginalis (treat partners)
Anaerobic infection / PID component

Adverse effects

Disulfiram-like reaction with alcoholclassic

Flushing, vomiting, tachycardia — avoid alcohol during and 48 h after.

Metallic taste, GI upsetcommon

Peripheral neuropathy (prolonged use)common

Cautions & contraindications

Alcohol useall

Disulfiram reaction.

Interactions

Alcohol (disulfiram)
Enhances warfarin

Monitoring & kinetics

Treat partner (trichomonas); BV recurrence common

Oral (topical metronidazole/clindamycin for BV; trichomonas needs systemic).

Choosing it

true

Source: BASHH — BV / Trichomonas