Warfarin and heparin are anticoagulants that help in blood thinning. The main difference is that heparin is a direct-acting anticoagulant and belongs to the group of medium-molecular heparins: whereas warfarin is an indirect anticoagulant. The onset of the anticoagulant effect is observed after 36-72 hours from the start of the drug, with the development of the maximum effect 5-7 days from the start of use. After discontinuation of the drug, restoring the activity of vitamin K-dependent blood clotting factors occurs within 4-5 days. The drug is rapidly absorbed from the gastrointestinal tract – binding to plasma proteins is 97-99%. Warfarin is used to treat and prevent thrombosis and embolism of blood vessels: acute and recurrent venous thrombosis.
Contraindications are established or suspected hypersensitivity to the drug’s components, acute bleeding, and pregnancy. Side effects include vomiting, nausea, diarrhea, and hypersensitivity to warfarin after prolonged use. Heparin belongs to the group of medium molecular-weight heparins (Sanomura et al., 2018). It activates antithrombin III in the blood plasma, accelerating its anticoagulant effect. Heparin increases renal blood flow and increases the resistance of brain vessels. When applied externally, the drug has a local antithrombotic, antioxidative, and moderate anti-inflammatory effect. Side effects include allergic reactions; other potential side effects include dizziness, headache, nausea, decreased appetite, and vomiting. Contraindications include hypersensitivity to heparin, and diseases accompanied by increased bleeding.
References
Kim, N. H. (2020). Fibrates revisited: potential role in cardiovascular risk reduction.Diabetes & Metabolism Journal, 44(2), 213-221.
Sanomura, Y., Oka, S., Tanaka, S., Yorita, N., Kuroki, K., Kurihara, M.,… & Chayama, K. (2018). Taking warfarin with heparin replacement and direct oral anticoagulant is a risk factor for bleeding after endoscopic submucosal dissection for early gastric cancer. Digestion, 97(3), 240-249.