First-lineFlagyl

Metronidazole

Nitroimidazole antibiotic

BV, trichomonas, anaerobic chorio/endometritis.

OralIVPV gel

First-line for

  • Bacterial vaginosis
  • Trichomonas vaginalis
  • Anaerobic cover (endometritis, septic abortion)

Mechanism

Reduced under anaerobic conditions → DNA strand breaks.

Metro 'No alcohol'

  • Disulfiram reaction — flushing, vomiting

Dosing

BV
400 mg PO BD ×7 days OR 2 g PO stat
Trichomonas
2 g PO stat (treat partner)

Contraindications

  • CautionT1 (avoid high-dose stat); alcohol use

Side effects

  • Metallic taste, nausea
  • Peripheral neuropathy (prolonged)

Fetal & maternal notes

  • Compatible after T1; high-dose stat avoided T1.
  • Single dose during BF — interrupt 12–24 h.

Key interactions

  • Alcohol

    Avoid

    Disulfiram-like reaction

  • Warfarin

    Avoid

    ↑ INR

  • Lithium / phenytoin

    Caution

    ↑ levels

Clinical pearls

  • 💡 BV: oral & PV equally effective.
  • 💡 Recurrent BV → 2× weekly suppression.

Content last reviewed: REPLACE_ME (e.g. 2026-07)

Spotted something out of date? See our disclaimer or use Report an Error above.

For educational use only

Not medical advice. Verify dosing against the BNF and your local trust guidelines before prescribing.