Treatment Side Effects

Because anticoagulants prevents blood from clotting, patients starting treatment for deep vein thrombosis are closely monitored. Side effects are uncommon, but should be reported to your physician immediately. If you are unable to contact your physician go to your nearest Emergency department. Side effects include:

• Any kind of unusual bleeding including:
• Blood in urine or feces (stools)
• Black feces (stools)
• Severe bruising
• Nose bleeds lasting more than 10 minutes
• Blood in vomit
• Coughing up blood
• In women, heavy or increased bleeding during menstruation or any other vaginal bleeding
• Unusual severe headaches
• Sudden severe back pain
• Difficulty breathing or chest pain

Other possible side effects of Low Molecular Weight Heparin (LMWH)

• Allergic reaction: if you develop a rash at the injection site, report this immediately to the Thrombosis Clinic.
• Heparin induced thrombocytopenia (HIT): if the injection site turns black or deep red, report this immediately to the Thrombosis Clinic. This side effect can also cause more clotting!

Other possible side effects of Warfarin

• Hair loss or thinning
• Diarrhea
• Rash

Warfarin can cause birth defects if taken by pregnant women. Women taking warfarin should take steps to avoid becoming pregnant during treatment.

Other possible side effects of DOACs

• Allergic reactions (apixaban, dabigatran, rivaroxaban)
• Stomach pain, heartburn and nausea (dabigatran)

Call your doctor urgently or go to the emergency department if you:

• Have bright red blood in your stool, urine or vomit
• Have black, tarry, very foul smelling stools
• Have sudden onset of a new, severe headache, especially if you are nauseated or drowsy
• Injure your head (even if minor) or have a bad fall
• Experience swelling and severe pain in a joint
• Have unexplained shortness of breath
• Have worsening pain and swelling in legs or arms
• Have new and severe chest pain
• Feel your heart is racing, especially if you are dizzy