Doptelet Avatrombopag Maleate Tablets

1. Indications and Usage
Chronic Liver Disease (CLD): Treatment of adult patients with thrombocytopenia who are scheduled for a diagnostic procedure or surgery.
Immune Thrombocytopenia (ITP): Treatment of adult patients with chronic primary ITP who have had an insufficient response to previous treatments (e.g., corticosteroids, immunoglobulins). It is used to increase platelet count and reduce the risk of bleeding.
2. Dosage and Administration
Administration: Oral administration. Must be taken with food (with meals) to ensure proper absorption.
Dosing for CLD (Pre-procedure):
Regimen: Once daily for 5 consecutive days. Start 10-13 days before the scheduled procedure.
Dose: 60 mg (3 tablets) daily if baseline platelets <40×10⁹/L; 40 mg (2 tablets) daily if baseline platelets are 40 to <50×10⁹/L.
Dosing for ITP (Maintenance):
Regimen: Start at 20 mg once daily. Adjust dose based on platelet count to maintain ≥50×10⁹/L.
Max Dose: 40 mg once daily.
3. Mechanism of Action
TPO Receptor Agonist: Avatrombopag is an orally available, small-molecule agonist of the thrombopoietin (TPO) receptor.
Pathway: It stimulates the proliferation and differentiation of bone marrow megakaryocytes, leading to increased platelet production. Unlike natural TPO, it does not compete with endogenous TPO for receptor binding .
4. Safety and Warnings
Thrombosis: The most significant risk is thrombosis or thromboembolic complications (e.g., portal vein thrombosis, DVT).
Platelet Count Monitoring: Dosage must be carefully managed to avoid raising platelet counts too high. For CLD patients, the goal is to raise platelets to a safe level for surgery, not to normalize them.
5. Adverse Reactions
Common Reactions: Pyrexia (fever), abdominal pain, nausea, headache, fatigue, peripheral edema.
Serious Reactions: Thrombosis (Portal vein thrombosis, Deep vein thrombosis).
6. Drug Interactions
CYP2C9 and CYP3A4: Avatrombopag is metabolized by these enzymes.
Inhibitors: Concomitant use with strong inhibitors (e.g., ketoconazole, itraconazole) may increase avatrombopag exposure and toxicity risk (monitor platelet count).
Inducers: Concomitant use with inducers may decrease efficacy.
P-gp Substrate: Avatrombopag is a P-gp substrate; co-administration with inhibitors (e.g., cyclosporine, verapamil) may increase exposure.
7. Pharmaceutical Information
Chemical Name: 1-(3-chloro-5-{[4-(4-chlorothiophen-2-yl)-5-(4-cyclohexylpiperazin-1-yl)-1,3-thiazol-2-yl]carbamoyl}pyridin-2-yl)piperidine-4-carboxylic acid maleate
Molecular Formula: C29H34Cl2N6O3S2 · C4H4O4
Storage: Store below 25°C. Keep container tightly closed.