ZEROBAN 20

Indications

• Prevention of venous thromboembolism (VTE) in patients undergoing hip or knee replacement surgery
• Treatment of deep vein thrombosis (DVT)
• Treatment of pulmonary embolism (PE)
• Prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation
• Prevention of VTE in acutely ill medical patients

Dosage

Children: Refer to the BNF for Children for appropriate dosing information in paediatric populations.

Adults: Refer to prescribing information for specific dosing guidelines based on condition and patient characteristics.

Mechanism of action

Rivaroxaban exerts its pharmacological effects by selectively and reversibly inhibiting factor Xa. This inhibition prevents the conversion of prothrombin to thrombin, thereby reducing thrombus formation and promoting anticoagulation.

Pharmacodynamics

Rivaroxaban demonstrates dose-dependent anticoagulant effects, which can be monitored through prothrombin time (PT) and anti-factor Xa activity. Its anticoagulant effect is predictable, allowing for fixed dosing without the need for routine coagulation monitoring in most patients. The onset of action occurs within 2 to 4 hours after oral administration, with a peak effect typically observed within 2 to 4 hours.

Pharmacokinetics

Rivaroxaban is rapidly absorbed, with peak plasma concentrations occurring approximately 2 to 4 hours post-dose. It has a high bioavailability of about 80% to 100% when taken with food. The drug is extensively metabolized in the liver, primarily by cytochrome P450 enzymes, and has a half-life of about 5 to 9 hours in healthy individuals. Rivaroxaban is primarily eliminated through urine (approximately 66%) and feces (approximately 28%).

Contra-indications

• Active bleeding disorders
• Severe renal impairment (CrCl < 15 mL/min)
• Active peptic ulcer disease
• Severe hepatic impairment (Child-Pugh class C)
• Hypersensitivity to rivaroxaban or any excipients

Adverse effects

• Bleeding complications
• Nausea
• Abdominal pain
• Headache
• Dizziness
• Elevated liver enzymes
• Rash

Interactions

• Strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) may increase rivaroxaban levels
• Strong CYP3A4 inducers (e.g., rifampicin, St. John's Wort) may decrease rivaroxaban levels
• Other anticoagulants (e.g., warfarin, dabigatran) may increase bleeding risk when used concurrently
• NSAIDs and antiplatelet agents may increase bleeding risk

Precautions

• Monitor renal function regularly
• Use with caution in patients with a history of bleeding disorders
• Consider the risk of bleeding in elderly patients
• Discontinue prior to surgical procedures to reduce bleeding risk

Pregnancy

Rivaroxaban is not recommended during pregnancy due to potential risk of bleeding and fetal harm.

Breast-feeding

It is not known if rivaroxaban is excreted in human breast milk; caution is advised when administering to nursing mothers.

Storage

Store at room temperature, away from moisture and light. Keep out of reach of children.

Formulations

• Tablets (10 mg, 15 mg, 20 mg)
• Oral suspension - none available