Warfarin - side effects

Warfarin is an anticoagulant of indirect action, which is a derivative of coumarin. The drug suppresses synthesis in the liver of vitamin-K dependent clotting factors. The concentration of these substances is reduced and, accordingly, the blood coagulability is slowed down. Dosage when taking Warfarin should be very accurate. In addition, patients taking this medication require regular blood tests to determine the INR (blood count, which characterizes its coagulability). Overdosing or improper intake of warfarin can cause internal bleeding and other side effects of varying severity, up to a lethal outcome.

Side Effects of Warfarin

During the administration of the drug, the following can be observed:

  1. Bleeding - quite often encountered with the use of Warfarin side effect. In mild form it can be limited by bleeding gums or the formation of small hematomas on the skin. In rare cases, anemia and local necrosis of the skin due to thrombosis may occur. Internal, and especially life-threatening patient intracranial hemorrhages, with observing the dosages of taking Warfarin, appear in about 1 out of 10,000 cases, and are most often associated with the presence of arterial hypertension and some other comorbidities.
  2. From the digestive system can be observed nausea, diarrhea, vomiting, abdominal pain. In rare cases - the development of jaundice.
  3. On the part of the nervous system, in rare cases, there may be increased fatigue, headaches, dizziness, and taste disturbances.
  4. In extremely rare cases with prolonged therapy with warfarin, there are complications from the respiratory system: tracheal or tracheo-bronchial calcification.
  5. With individual hypersensitivity or intolerance of the drug, skin rash, itching, dermatitis, vasculitis , alopecia (hair loss) can be observed.

Overdose Warfarin

Effective for treatment of the dose of the drug is on the verge of bleeding, which is why the control of INR and compliance with prescribed dosages in the treatment of warfarin plays such a large role. With small bleedings, usually the drug is skipped or the dose is reduced. When an overdose associated with the development of severe bleeding, use intravenous vitamin K (neutralizing the effect of Warfarin), as well as fresh-frozen blood plasma or coagulation factor concentrates.

Control of INR when taking Warfarin

MNO is the international normalized ratio, the clotting factor, which is calculated from the prothrombin index. Than this indicator is lower, the blood is thicker and there is more risk of blood clots. A high MNO indicates a risk of bleeding. At the initial stage, when selecting the necessary dosage of the drug, the indicator is measured daily. In the future it is recommended to conduct the analysis once a week, and if 3-4 measurements remain within the permissible norm, the frequency of the INR assay can be reduced to once in 2 weeks. Additional analysis on INR is required in the case of changes in diet, stress, and other factors that may affect the indicator.

Food when taking Warfarin

Food containing a large amount of vitamin K can reduce the effectiveness of the drug. A large amount of this vitamin is found in fresh greens, so in the treatment should not be abused by products such as:

Warfarin and alcohol

Alcohol enhances the anticoagulant effect of warfarin and as a result, the occurrence of unstable bleeding may occur even with minor domestic trauma. Taking a large dose of alcohol along with warfarin is fraught with the development of severe internal bleeding, primarily of the stomach, which is life-threatening.