Tell me the main side effects of anticoagulant medicines

A possible side effect of anticoagulants is excessive bleeding (haemorrhage), because these medicines increase the time it takesfor Arterial thrombosis to form.

Some people also experience other side effects.

Excessive bleeding

Signs of excessive bleeding can include:

  • passing blood in your urine
  • passing blood when you poo or having black poo
  • severe bruising
  • prolonged nosebleeds (lasting longer than 10 minutes)
  • bleeding gums
  • vomiting blood or coughing up blood
  • sudden severe back pain
  • difficulty breathing or chest pain
  • in women, heavy or increased bleeding during your periods , or any other bleeding from your vagina

If you notice any severe or recurrent bleeding, seek medical attention immediately. Contact your GP or go to your nearest accident and emergency (A&E) department .

Youshould also seek immediate medical attention if you:

  • are involved in a major accident
  • experience a significant blow to the head
  • are unable to stop any bleeding

If you're taking warfarin, you'll have regular blood tests to check if you'reat a high risk ofexcessive bleeding by measuring how quickly your blood clots. If your blood clots too slowly, your dose may be increased.

Other side effects

Other side effects of anticoagulants vary depending on which medication you're taking.

For a full list of potential side effects for your medicine,check the leaflet that comes with it.

Possibleother side effects include:

  • diarrhoea or constipation
  • feelingandbeingsick
  • indigestion
  • dizziness
  • headaches
  • rashes
  • itchy skin
  • hair loss
  • jaundice (yellowing of the skin and whites of the eyes)

Speak to your GP or anticoagulant clinic if you have any persistent troublesome side effects. Contact them immediately if you develop jaundice.

Content supplied by the NHS Website

Medically Reviewed by a doctor on 6 Dec 2016