Phytomenadione (Vitamin K1)

Source product is Konakion MM / Phytomenadione 10 mg/1 ml solution for injection. LESS SEVERE HAEMORRHAGE / asymptomatic high INR on warfarin (SPC states these are 'for therapeutic guidance only'): INR 5-9 — 0.5 to 1.0 mg IV; INR >9 — 1.0 mg IV. 'For small doses one or more ampoules of Konakion MM Paediatric/Phytomenadione 2 mg/0.2 ml solution for injection (same solution) can be used.' Treatment of asymptomatic raised INR depends on the underlying indication for anticoagulation, the INR value, time spent outside the therapeutic range, patient characteristics (age, comorbidity, concomitant medication) and the associated risk of major bleeding. NON-WARFARIN ANTICOAGULANTS: 'The dosing recommendations above apply to patients taking warfarin. There are limited data regarding reversal of the effects of other anticoagulants, such as acenocoumarol or phenprocoumon. The half-lives of these anticoagulants are different to warfarin and different doses of vitamin K1 may be required.' ELDERLY: 'Elderly patients tend to be more sensitive to reversal of anticoagulation... The dosage for this patient group should therefore be at the lower end of the ranges recommended.' §4.4 cautions: large doses (not more than 40 mg per day) should be avoided if it is intended to continue anticoagulant therapy; vitamin K1 is not an antidote to heparin; the use of vitamin K1 in patients with mechanical heart valves is generally to be avoided unless there is major bleeding, and FFP should be used if such patients are transfused for severe haemorrhage; one 1 ml ampoule contains 54.6 mg glycocholic acid which may displace bilirubin in severe hepatic impairment. NEONATES AND BABIES: 'Konakion MM Paediatric/Phytomenadione 2 mg/0.2 ml solution for injection should be used in these patients (see separate prescribing information)' — not covered by this SPC.

Children aged 1 to 18 years, asymptomatic high INR with or without mild haemorrhage. Verbatim: 'Intravenous vitamin K1 at doses of 30 micrograms/kg have been reported to be effective in reversing asymptomatic high (>8) INR in clinically well children.' Separately, for CHILDREN WITH MAJOR AND LIFE-THREATENING BLEEDING the SPC suggests a flat dose, not a per-kg dose: 'A dose of 5 mg vitamin K1 IV is suggested (together with PCC if appropriate, or FFP if PCC is not available).' The SPC states there are few data in children over 1 year and no dose-ranging studies in children with haemorrhage, that 'The optimal dose should therefore be decided by the treating physician according to the indication, clinical situation and weight of the patient', and that a haematologist should be consulted. Neonates and babies require the 2 mg/0.2 ml paediatric presentation (separate prescribing information). Verify all paediatric dosing against a children's formulary before use.