Vitamin K

Fat-Soluble·Vitamins & Minerals

Warfarin reversal, severe liver disease coagulopathy, Vitamin K deficiency bleeding in neonates

VITAMINKonakion MMThe IV ampoule liquid (Konak…S4TGA

Max Dose

10 mg (STAT)

Onset

6-24 h

Anaphylaxis

IV RISK

Route

PO or IV

Rapid Summary

Overview

Phytomenadione. Essential cofactor for the hepatic synthesis of clotting factors II, VII, IX, and X. The definitive antidote for Warfarin overdose/toxicity.

Maximum Dose

Max 10 mg (STAT) for severe bleeding on Warfarin.

Clinical Focus

IV Vitamin K carries a rare but severe 'black box' risk of anaphylaxis. Must be run slowly. SC/IM routes are erratic and should be avoided.

Bottom Line

Vitamin K is essential for reversing warfarin over-anticoagulation and treating haemorrhagic disease of the newborn, but IV administration carries rare anaphylaxis risk and takes 6-12 hours for full effect.

Formulation & Access

Brand Names

Konakion MM

Oral Routes

The IV ampoule liquid (Konakion MM) can be drawn up in a syringe and given orally.

Parenteral

Ampoules (10 mg/1 mL) for IV infusion or oral administration. Ampoules (2 mg/0.2 mL) for paediatric IM.

Prescribing & PBS

Hospital supply. S4.

Indications & Use

Primary

TGA

Warfarin reversal, severe liver disease coagulopathy, Vitamin K deficiency bleeding in neonates.

Clinical Place

Mandatory antidote for supratherapeutic INRs. Takes time to work; not an instant fix.

Quick reference

Class & Role

Fat-Soluble — Phytomenadione.

Route / Formulation

The IV ampoule liquid (Konakion MM) can be drawn up in a syringe and given orally. (Konakion MM)

Usual Dose & Max

PO 1-3 mg STAT. Recheck INR in 24 hours. Max 10 mg (STAT) for severe bleeding on Warfarin.

Key Indication Doses

Warfarin Reversal (Minor bleed / High INR): PO 1-3 mg STAT. Recheck INR in 24 hours. Warfarin Reversal (Major Bleeding): IV 5-10 mg STAT (diluted in 50mL glucose/saline, run over 30 mins) PLUS Prothrombinex-VF. Neonatal Prophylaxis: IM 1 mg STAT immediately after birth to prevent Haemorrhagic Disease of the Newborn.

Best Uses

Avoid / Cautions

DOAC Reversal. Vitamin K is completely useless for reversing Rivaroxaban or Apixaban (they do not rely on Vitamin K). Pregnancy Category A.

Key Risks

Immunological: Severe anaphylactoid reaction, shock, and cardiac arrest associated with rapid IV bolus. (Caused by the polyethoxylated castor oil suspension vehicle, not the vitamin itself). Haematological: Re-starting Warfarin is incredibly difficult for 1-2 weeks after a large dose (10 mg) of Vitamin K, leaving the patient exposed to clotting risks.

Key Interactions

Warfarin. Vitamin K directly antagonises it. Bile acid sequestrants (Cholestyramine) and Orlistat block fat-soluble vitamin absorption in the gut. Avoid giving PO Vitamin K with them.

Monitoring

Monitor INR 6-12 hours after IV administration, or 24 hours after oral administration. Infuse IV formulations slowly (over at least 30 mins) while monitoring BP and HR to prevent anaphylactoid shock.

Clinical Pearl

Never give Vitamin K subcutaneously (SC). In a shocked or bleeding patient, SC tissue shuts down. The drug will sit in the fat and do absolutely nothing. Use PO or IV.

Access

Konakion MMThe IV ampoule liquid (Konak…

Brand: Konakion MM
Formulation: The IV ampoule liquid (Konakion MM) can be drawn up in a syringe and given orally