Betrixaban

Betrixaban is a direct oral anticoagulant (DOAC) that selectively inhibits factor Xa, reducing thrombin generation and helping to prevent clot formation. It is used for extended prophylaxis of venous thromboembolism in adults after hospitalization for an acute medical illness.

Betrixaban was developed by Portola Pharmaceuticals and was approved by the U.S. Food and Drug Administration in 2017 for the prevention of DVT following acute medical illness requiring hospitalization. It is marketed under the brand name Bevyxxa. It is not approved for treatment of active venous thromboembolism or for stroke prevention in nonvalvular atrial fibrillation.

Administration and dosing: The recommended regimen for patients with normal renal function is a single 160 mg dose on day 1, followed by 80 mg once daily for 35 to 42 days. Dose adjustments or avoidance are necessary in patients with renal impairment or other contraindications. Betrixaban has a relatively long half-life, supporting once-daily dosing.

Pharmacokinetics and interactions: Betrixaban is an oral agent with predictable pharmacokinetics and does not require routine coagulation monitoring. It is a substrate of P-glycoprotein and is largely excreted renally and via bile; strong inhibitors or inducers of P-gp can affect exposure. It is not extensively metabolized by cytochrome P450 enzymes, which can influence the profile of drug interactions compared with some other anticoagulants.

Safety: Bleeding is the principal safety concern, with risk increasing in older patients, those with renal impairment, or when used with other antiplatelet therapies. Contraindications include active major bleeding and significant hepatic impairment; use requires careful assessment of bleeding risk.