Vitamin K

 British Haematology Guideline on the management of bleeding in patients on antithrombotic agents 2012

 Addendum to the above guideline 2018 - advice on reversing dabigatran.

Vitamin K is essential for the production of blood clotting factors, antagonises effects of oral anticoagulants.

Menadiol (synthetic water soluble formulation) is preferred in fat malabsorption syndromes and in obstructive liver disease.

Phytomenadione (fat soluble formulation) is used to antagonise the effects of vitamin K antagonist oral anticoagulants, e.g. warfarin. It is ineffective against the newer oral anticoagulants. It is also used to prevent vitamin K deficiency bleeding in neonates (hemorrhagic disease of the newborn).

Konakion MM Paediatric can be administered orally, intramuscularly or intravenously. 1mg is given as a single IM dose at birth. A second dose of 2mg is given orally at 7 days. In breast fed infants a third dose is due at one month. The third dose is omitted in formula fed infants because formula feeds contain vitamin K.

Konakion MM contains a mixed micelles preparation for intravenous injection in adults. It should be administered in 50ml of 5% glucose. Reversal of anti-coagulation with vitamin K is achieved more rapidly with IV administration than oral administration. In patients with major bleeding, IV administration is preferable; a dose of 5 or 10mg is recommended in addition to factor replacement therapy with either factor concentrate or Fresh Frozen Plasma (FFP).