Vitamin / Haemostatic Pregnancy: A — safe in pregnancy (used for maternal anticoagulant reversal)

Vitamin K (Phytomenadione)

Brand names: Konakion MM Paediatric

Adult dose

Dose: Reversal of anticoagulation: 1–10mg slow IV or oral

Route: IV or Oral

Frequency: Single dose or as needed

Warfarin reversal: 1–5mg IV (INR >8 or bleeding). Life-threatening bleeding: 5–10mg IV. Non-urgent: 1–2.5mg oral.

Paediatric dose

Route: IM or Oral

Frequency: At birth

VKDB prophylaxis: 1mg IM at birth (all neonates — NHS routine). Oral: 2mg at birth, 2mg at 1 week, 2mg at 4–6 weeks (breastfed). Premature <32 weeks: 0.4mg/kg IM (max 1mg).

Clinical pearls

UK recommendation: 1mg IM at birth for ALL neonates — prevents Vitamin K Deficiency Bleeding (VKDB/HDN)
Breastfed infants at higher risk (breast milk low in vitamin K vs formula-enriched)
IM single dose is more effective than 3-dose oral regimen for late VKDB prevention
Late VKDB (2–12 weeks): presents as intracranial haemorrhage in exclusively breastfed infants not given prophylaxis
IV: slow infusion only — bolus can cause anaphylaxis and flushing

Contraindications

IV bolus route (risk of anaphylaxis — give by slow IV infusion only)

Side effects

Anaphylaxis (IV bolus — rare)
Injection site reaction (IM)
Flushing (rapid IV infusion)

Interactions

Warfarin — direct antagonist
Mineral oil — reduces oral absorption

Monitoring

INR (reversal of anticoagulation)
Signs of bleeding in neonates not given prophylaxis

Reference: BNFc; RCPCH/BAPM Vitamin K Guidelines; BNF for Children. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways