Patients with Chronic Liver Disease
- PO (Adults): Platelet count <40 × 109/L: 60 mg once daily for 5 days (should be initiated 10–13 days prior to scheduled procedure; procedure should be performed 5–8 days after last dose); Platelet count 40–<50 × 109/L: 40 mg once daily for 5 days (should be initiated 10–13 days prior to scheduled procedure; procedure should be performed 5–8 days after last dose.
Patients with Chronic Immune Thrombocytopenia
- PO (Adults): Dose levels recommended for titration of therapy based on platelet counts: Dose Level 1: 20 mg once weekly; Dose Level 2: 20 mg twice weekly OR 40 mg once weekly; Dose Level 3: 20 mg 3 times weekly; Dose Level 4: 20 mg once daily; Dose Level 5: 40 mg 3 times weekly AND20 mg the remaining 4 days of the week; Dose Level 6: 40 mg once daily; Initiate therapy at Dose Level 4 (20 mg once daily); if platelet count <50 × 109/L after 2 wk of therapy, ↑ one Dose Level; if platelet count 50–200 × 109/L after 2 wk of therapy, continue current Dose Level; if platelet count 200–400 × 109/L after 2 wk of therapy, ↓ one Dose Level; if platelet count >400 × 109/L, discontinue avatrombopag and restart therapy (↓ one Dose Level) once platelet count <150 × 109/L. Concurrent use of moderate or strong dual inhibitors of CYP3A4 and CYP2C9: Initiate therapy at Dose Level 3 (20 mg 3 times weekly). Concurrent use of moderate or strong dual inducers of CYP3A4 and CYP2C9: Initiate therapy at Dose Level 6 (40 mg once daily).
Therapeutic Classification: antithrombocytopenics
Pharmacologic Classification:
Absorption: 66–69% absorbed following oral administration.
Distribution: Widely distributed to tissues.
Protein Binding: >96%.
Metabolism/Excretion: Primarily metabolized by CYP2C9 and CYP3A4 isoenzymes; the CYP2C9 enzyme system exhibits genetic polymorphism (intermediate or poor metabolizers may have significantly ↑ avatrombopag concentrations and an ↑ risk of adverse effects).. Primarily eliminated in feces (34% as unchanged drug).
Half-life: 19 hr.
(effect on platelet count)
