Anticoagulant-Associated Bleeding

How blood thinners cause bleeding

Anticoagulants reduce the blood's ability to form clots, which prevents strokes in atrial fibrillation and treats or prevents deep vein thrombosis and pulmonary embolism. The same effect means that when a blood vessel is injured, bleeding lasts longer and can be heavier.

DOACs carry a lower risk of bleeding in the brain than warfarin, though gut bleeding is similar or higher with some.

Types of bleeding

Minor bleeding

Easy bruising, nosebleeds, gum bleeding, small cuts that ooze and slightly heavier periods. These are common and usually do not require stopping the medicine. Mention them to your doctor if they are frequent.

Major bleeding

• Intracranial bleeding: bleeding in or around the brain. The most feared complication. It can follow even a minor head bump, sometimes hours or days later.
• Gastrointestinal bleeding: from ulcers, diverticula or tumors. Black stools, blood in stools, vomiting blood, or anemia.
• Urinary bleeding: blood in the urine. Persistent blood in the urine on anticoagulants still needs investigation, because the drug can unmask an underlying problem such as a bladder tumor or stone.
• Muscle and retroperitoneal bleeding: painful swelling in a thigh, or back and flank pain.
• Joint bleeding: a swollen, painful joint.

Risk factors for bleeding

• age over 65 to 75
• kidney or liver disease
• previous major bleeding, ulcers or stroke
• uncontrolled high blood pressure
• anemia or low platelets
• taking aspirin, clopidogrel, NSAIDs (ibuprofen, naproxen), SSRIs or some supplements (fish oil, ginkgo, high-dose vitamin E, turmeric)
• heavy alcohol use
• falls
• for warfarin, an INR above the target range from interactions or diet changes; see warfarin toxicity

Doctors use scores such as HAS-BLED to identify fixable risk factors. A high score is a reason to correct those factors, not usually a reason to stop anticoagulation.

How bleeding on anticoagulants is assessed

In the ER, doctors will:

1. Check blood pressure, heart rate and the site of bleeding.
2. Ask which anticoagulant you take, the dose and when you took the last dose. Carry a medicine card.
3. Order blood tests: blood count, kidney function, INR (warfarin), and sometimes drug-specific levels.
4. Arrange imaging: a CT scan of the head after any head injury or neurological symptom, or endoscopy for gut bleeding.

Treatment

Minor bleeding

• Nosebleed: sit up, lean forward and pinch the soft part of the nose for 10 to 15 minutes without letting go.
• Cuts: firm, continuous pressure for 10 minutes, then a dressing.
• Gum bleeding: soft toothbrush and gentle flossing; see a dentist.
• Usually continue the anticoagulant, but tell your doctor.

Major or life-threatening bleeding

• Stop the anticoagulant.
• Supportive care: fluids, blood transfusion, and treatment of the source by endoscopy, surgery or procedures.
• Reversal: - warfarin: intravenous vitamin K plus four-factor prothrombin complex concentrate - dabigatran: idarucizumab - apixaban and rivaroxaban: andexanet alfa or prothrombin complex concentrate - heparin: protamine
• Activated charcoal if a DOAC was taken within the last few hours.

Restarting the blood thinner

Because the reason for the anticoagulant (stroke or clot risk) persists, most people restart once bleeding is controlled. The timing depends on the bleeding site, often within days to weeks for gut bleeding and later for brain bleeding. For people with atrial fibrillation who cannot safely take anticoagulants, a left atrial appendage closure device may be an option.

Preventing bleeding on blood thinners

• Take the exact dose at the same time daily. Never double up after a missed dose without checking the leaflet or a pharmacist.
• Tell every doctor, dentist and pharmacist that you take an anticoagulant.
• Avoid NSAIDs. Use acetaminophen (paracetamol) for pain, within the label dose.
• Check with a pharmacist before starting antibiotics, antifungals, supplements or herbal products.
• Limit alcohol.
• Reduce fall risk: good lighting, no loose rugs, proper footwear, and treat dizziness.
• Use an electric razor and a soft toothbrush.
• On warfarin, keep vitamin K intake (leafy greens) steady rather than avoiding it, and keep INR tests on schedule.
• Wear a medical alert bracelet.

Frequently asked questions

What are the signs of internal bleeding on blood thinners?

Warning signs include black or bloody stools, vomiting blood or coffee-ground material, red or brown urine, severe headache or confusion, unusual weakness, dizziness or fainting, and unexplained swelling or pain in the belly, back or thigh. These need emergency care.

Is bruising normal on Eliquis or Xarelto?

Some extra bruising is common on apixaban (Eliquis) and rivaroxaban (Xarelto) and is usually harmless. Tell your doctor if bruises are large, appear without injury, keep increasing, or come with other bleeding such as nosebleeds, blood in urine or dark stools.

What should I do if I hit my head while on a blood thinner?

Seek medical assessment the same day, even if you feel fine. Bleeding inside the skull can develop slowly. Doctors often recommend a CT scan after head injuries in people on anticoagulants. Go to the ER immediately for headache, vomiting, confusion or drowsiness.

Can blood thinners be reversed?

Yes. Warfarin is reversed with vitamin K and prothrombin complex concentrate. Dabigatran has a specific antidote, idarucizumab. Apixaban and rivaroxaban can be reversed with andexanet alfa or prothrombin complex concentrate. Heparin is reversed with protamine.

Can I take ibuprofen with a blood thinner?

It is best avoided. NSAIDs such as ibuprofen and naproxen increase the risk of stomach bleeding and interfere with platelets. Acetaminophen (paracetamol) is usually the safer choice for pain. Ask your doctor or pharmacist before using any new pain medicine.