Heparin

Comes as:InjectionDrip (infusion)

Usual adult dose

Given by injection or drip, usually in hospital. To prevent clots: 5000 units under the skin every 8 to 12 hours. Treatment doses are set by your doctor and checked with blood tests.

Your doctor may give you a different dose. Children's doses depend on weight.

Side effects

Common

bruising or pain at the injection site

Serious — get help

Stop taking it and see a doctor straight away if you notice:

serious bleeding
low platelets with new clots
severe allergic reaction
high potassium

Do not take it, or take care, if

Active bleeding
Low platelets, or past low platelets caused by heparin
Severe uncontrolled high blood pressure
Recent bleeding in the brain

Interactions

Medicines that can react with this one.

Moderate3 medicinesTake together only with care. Ask your doctor or pharmacist.

Aspirin
Together they raise the risk of bleeding.
Ibuprofen
NSAIDs with heparin raise the risk of bleeding.
Warfarin
Used together when starting warfarin, but bleeding risk is higher and needs blood tests.

Blood thinners