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What is Oral direct Xa inhibitor: and explain in detail?
Ans. a. Rivaroxaban Ref: Goodman Gilman 13th E/P595 Oral factor Xa Inhibitors: Apixaban Rivaroxaban Edoxaban Oral factor Xa inhibitors along with oral direct thrombin inhibitor dabigatran are collectively known as NOAC (Novel Oral Anticoagulants) or DOAC (Direct Oral Anticoagulants). These are the current drug of choice for prophylaxis of thrombosis in atrial fibrillation and patients undergoing hip and knee surgery. However, these drugs are contraindicated in patients with mechanical heart valves. All drugs of this class can be used for treatment of acute venous thrombosis, but only after 5 days of treatment with heparin or fondaparinux (heparin bridge), except rivaroxaban and apixaban which can be started immediately. The biggest benefit of these drugs is that no monitoring is required. The recent drug approved for reversal of oral factor Xa inhibitor induced bleeding is known as andexanet alfa. Whereas for dabigatran induced bleeding idarucizumab is used. Ciraparantag is a new drug under trial for reversal of bleeding caused by heparin (UFH and LMWH), fondaparinux and the NOACs.