phytomenadione at a glance
Medicine class
Vitamin K1; an antihaemorrhagic vitamin.
Main roles
Prevention and treatment of vitamin K deficiency bleeding in babies, and reversal of coumarin anticoagulants.
Administration
Depending on the product and reason for treatment, it may be given by mouth or by injection.
Monitoring
When used to reverse warfarin, clotting results such as the INR need follow-up.
What is phytomenadione used for?
Selected products are licensed for:
Preventing and treating vitamin K deficiency bleeding in neonates and infants.
Preventing vitamin K deficiency bleeding in healthy babies using the oral capsule product.
Specialist reversal of coumarin anticoagulants in infants and children.
Treating bleeding or threatened bleeding caused by coumarin anticoagulants in adults.
Specialist services may supply oral preparations to lower a high INR outside licensed use.
How does phytomenadione work?
Phytomenadione helps the liver produce clotting factors II, VII, IX and X, and proteins C and S. Replacing vitamin K1 corrects impaired clotting caused by deficiency and counteracts medicines such as warfarin that block vitamin K activity.
phytomenadione preparations and strengths
Capsule
Route: Oral
Strengths: 1 mg
Injection
Route: Parenteral
Strengths: 2 mg/0.2 mL, 10 mg/1 mL, 10 mg/mL
How to take phytomenadione
How it is given depends on the formulation and reason for treatment. Follow instructions from the maternity, anticoagulation or specialist team.
The adult injection is given intravenously by a healthcare professional.
The paediatric mixed-micelle product may be given by mouth or injection, depending on the indication.
For the oral soft capsule, cut off the narrow tip and squeeze the liquid directly into the baby’s mouth. Do not give the capsule shell.
Do not use an ampoule if its contents are cloudy or separated.
phytomenadione side effects
Get urgent medical advice
- Severe allergy-like reactions have been reported after intravenous administration.
- Rarely, injection-site inflammation, tissue wasting or tissue damage may occur with the paediatric injection.
- Venous irritation or phlebitis has been reported very rarely with the adult intravenous formulation.
phytomenadione in pregnancy
Evidence for the adult injectable product during pregnancy is limited. It should be used only when the expected benefit outweighs the risk and is not recommended as maternal treatment solely to prevent vitamin K deficiency bleeding in the newborn; the baby is offered vitamin K directly after birth.
phytomenadione while breastfeeding
Only small amounts of vitamin K1 are present in breast milk, so breastfeeding does not replace the baby’s own vitamin K prevention. If treatment is needed for a breastfeeding parent, the prescriber should assess the indication and formulation because product-specific maternal-treatment data are limited.
phytomenadione interactions
The main clinically important interaction is with vitamin K antagonist anticoagulants.
Warfarin and other coumarin anticoagulants
Phytomenadione reverses their anticoagulant effect and may make subsequent anticoagulation harder to re-establish. Clotting tests and the ongoing need for anticoagulation must be reviewed.
Heparin
Phytomenadione does not reverse heparin and should not be used as its antidote.
Common questions about phytomenadione
Answers are fully visible for fast scanning and source review.
Is phytomenadione the same as vitamin K?
It is vitamin K1, also called phylloquinone, used in these products to support normal clotting.
Why is phytomenadione offered to newborn babies?
Newborns have low vitamin K stores and can rarely develop serious vitamin K deficiency bleeding. Giving vitamin K directly to the baby reduces this risk.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.