This site is intended for UK healthcare professionals
Medscape UK Univadis Logo
Medscape UK Univadis Logo

Phytomenadione parenteral

Updated 2 Feb 2023 | Vitamin K


Injection containing 10mg phytomenadione (Vitamin K1) per 1ml in a mixed micelles vehicle of glycocholic acid and lecithin.

Drugs List

  • phytomenadione 10mg/1ml solution for injection ampoule
  • Therapeutic Indications


    Antidote to coumarin-type anticoagulant overdosage

    Treatment as an antidote to anticoagulant drugs of the coumarin type in the treatment of haemorrhage or threatened haemorrhage, associated with a low blood level of prothrombin or factor VII.

    Treatment in children can be considered in disorders that interfere with absorption of vitamin K, poor nutrition and hepatic disease.


    Patients should stop the anticoagulant coumarin. Dose recommendations are based on warfarin anticoagulant therapy. Other anticoagulants (such as acenocoumarol) have different half lives and phytomenadione dose requirements may differ. Prothrombin complex concentrate (PCC) to be given together, particularly in severe or life-threatening haemorrhage. Fresh frozen plasma (FFP) can be given if PCC is not available.


    Potentially fatal or severe haemorrhages
    5mg to 10 mg of phytomenadione by slow intravenous injection.
    Maximum dose: 40mg in 24 hours.

    Less severe haemorrhage
    INR greater than 9: Give 1mg.
    INR between 5 and 9: Give 500micrograms to 1mg.

    Reversal of anticoagulation prior to surgery
    Emergency surgery that can be delayed 6 to 12 hours: Give 5mg intravenously.
    Elective surgery (unlicensed): Give 1mg to 5mg phytomenadione using the intravenous solution orally. If INR greater than or equal to 1.5, give dose on the day before surgery.

    The following alternative dosing schedules may be suitable:
    INR greater than 8 with minor bleeding
    Give 1mg to 3mg. Repeat if INR still too high after 24 hours. Restart warfarin when INR less than 5.
    INR greater than 8 with no bleeding
    Give 1mg to 5mg. Repeat if INR still too high after 24 hours. Restart warfarin when INR less than 5.
    INR 5 to 8 with minor bleeding
    Give 1mg to 3mg. Restart warfarin when INR less than 5.


    Dosage should be at the lower end of the ranges recommended as elderly patients tend to be more sensitive to reversal of anticoagulation with phytomenadione.


    Children aged 1 to 18 years
    Suggested dosages based on clinical experience are as follows:
    Major and life threatening bleeding
    5mg intravenously.
    Children with asymptomatic high INR with or without mild haemorrhage
    30micrograms/kg intravenously. Repeat if necessary.

    Patients with Hepatic Impairment

    Phytomenadione mixed micelles injection contains 54.6mg glycocholic acid per ampoule and this may have a bilirubin displacing effect.


    To be administered by slow intravenous injection or intravenous infusion.


    Children under 1 year

    Precautions and Warnings

    Children aged 1 to 18 years
    Prosthetic heart valve
    Severe hepatic impairment

    Fresh frozen plasma should be used in patients with prosthetic heart valves
    Patients with prosthetic heart valves: only use if there is major bleeding
    Children under 18 treatment should be initiated/supervised by haematologist
    Administer IV injection slowly
    Use only if the solution is clear
    Monitor international normalised ratio (INR)
    Severe haemorrhage: consider transfusion of whole blood or clotting factors
    May cause anaphylactic / anaphylactoid reactions
    Reduce dose in elderly

    It should be noted that the earliest effect seen with phytomenadione treatment is at 4-6 hours.

    This is not an antidote to heparin.

    Large doses of greater than 40 mg should be avoided if it is intended to continue with anticoagulant therapy as there is no experience with doses above 40 mg/day and higher doses may give rise to unexpected adverse events.

    Children under 18 years
    In patients on warfarin therapy, consider reason for warfarin treatment and whether or not anticoagulant therapy is likely to be continued e.g. child with mechanical heart valve or repeated thromboembolic complications, as vitamin K is likely to interfere with anticoagulation with warfarin for 2 - 3 weeks.

    Pregnancy and Lactation


    Use phytomenadione with caution during pregnancy.

    The manufacturer does not recommend using phytomenadione unless the clinical benefits outweigh the risks. At the time of writing there is limited published information regarding the use of phytomenadione during pregnancy.


    Use phytomenadione with caution during breastfeeding.

    The manufacturer does not recommend breastfeeding whilst taking phytomenadione unless the clinical benefits outweigh the risks. The presence phytomenadione in human breast milk and its effects on exposed infants are unknown.

    Side Effects

    Anaphylactoid reaction
    Hypersensitivity reactions
    Venous irritation


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: July 2021

    Reference Sources

    Summary of Product Characteristics: Phytomenadione 10mg/1ml solution for injection ampoules. Cheplapharm Arzneimittel GmbH. Revised October 2020.

    NICE Evidence Services Available at: Last accessed: 06 July 2021

    Access the full UK drug database with a FREE Medscape UK Account
    It takes just a few minutes, and you’ll get unlimited access to information on over 11,000 UK drugs.
    Register for Free

    Already a member? Log in

    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

    FDB Logo

    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.