Phytomenadione (Vitamin K₁)

Haematology

Haematology · Vitamin/anticoagulant reversal

Phytomenadione (Vitamin K₁)

Dose

1–2 mg IV for INR 5–8 with bleeding; 5–10 mg IV plus PCC for major bleeding; 1 mg IM to all neonates.

Use

Warfarin reversal, vitamin K deficiency, neonatal haemorrhagic disease prophylaxis.

Monitoring

INR at 6–12 h after IV dose.

Side effects

  • Anaphylactoid reaction with rapid IV push
  • Warfarin resistance for up to a week after large doses

Related in WardRound

Always confirm dose against your local formulary / BNF before prescribing.

WardRound

WardRound

Clinical Decisions in Seconds