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Phytomenadione injection

Konakion MM

Phytomenadione is a man-made form of vitamin K.

It is used to treat people who are at risk of bleeding because of taking anticoagulant medicines.

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About phytomenadione

Type of medicine

A form of vitamin K; an antihaemorrhagic

Used for

To prevent bleeding caused by anticoagulant medicines; to reverse the anticoagulant effects of warfarin before an operation

Also called

Phytonadione (in US); Konakion® MM

Available as

Injection for intravenous or oral use

Vitamin K is a fat-soluble vitamin which is essential for blood clotting. It also plays a role in bone health.

People who take anticoagulant medicines such as warfarin are at risk of bleeding. Regular blood tests are needed to check on how quickly the blood clots. The aim is to get the dose of warfarin just right so that the blood does not clot as easily as normal, but not so much as to cause bleeding problems. If the dose of the anticoagulant is too high then bleeding can become a problem. Phytomenadione is given as an antidote to bleeding caused by anticoagulant medicines such as warfarin. It is likely to be given by injection in hospital.

If a person who is taking a medicine like warfarin needs to have an operation at short notice then the effects of the anticoagulant medicine will need to be reversed before the surgery takes place. Vitamin K is given to reduce the risk of bleeding during the surgery.

Vitamin K is given to newborn babies soon after birth to prevent possible bleeding problems. It is usually given as an injection but the liquid medicine can also be swallowed. If you have been asked to give the medicine by mouth, your doctor or midwife will give you instructions on how much to give and when.

Before having phytomenadione

To make sure that this is the right treatment for you it is important that your doctor knows:

  • If you are pregnant or breastfeeding.

  • If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

  • If you have ever had an allergic reaction to a medicine.

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How phytomenadione is given

  • Phytomenadione injection will be given by a doctor or nurse. Ask to read the manufacturer's printed information leaflet from inside the pack - it will give you more information about treatment with phytomenadione.

  • You may be given the injection to swallow by mouth. This is often the case for people who are taking phytomenadione before surgery, or who have abnormal blood results but who do not have any symptoms of bleeding.

  • If you have been asked to give phytomenadione to your newborn baby by mouth, follow the midwife's or doctor's instructions carefully. Read the printed manufacturer's instructions on how to use the ampoule and dropper. A dose is usually needed at 1 week old and then at 1 month old.

Getting the most from your treatment

  • If you have any questions about your treatment, please ask your doctor or nurse for further advice.

  • After you have left hospital, remember to keep your regular clinic appointments so that your progress can be monitored.

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Can phytomenadione cause problems?

Very occasionally there have been reports of irritation or allergic-type reactions, but otherwise the medicine is unlikely to cause side-effects. If you experience any other symptoms which you think could be due to phytomenadione, please speak with your doctor or pharmacist for further advice.

How to store phytomenadione

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

If you buy any medicines 'over the counter', check with a pharmacist that they are safe to take with your prescribed medicines.

If you are due to have an operation or dental treatment, please tell the person carrying out the treatment which medicines you are taking.

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine, ask your doctor or pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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