Aopushu Macitentan Tablets

1. Indications and Usage
Pulmonary Arterial Hypertension (PAH): Indicated for the treatment of adult patients with pulmonary arterial hypertension (WHO Group 1) to delay disease progression and reduce the risk of PAH-related hospitalization.
2. Dosage and Administration
Recommended Dosage: 10 mg taken orally once daily with or without food.
Renal/Hepatic Impairment: No dosage adjustment is required for mild or moderate renal or hepatic impairment.
Administration Details: The tablet should be swallowed whole.
3. Mechanism of Action
Dual Receptor Antagonism: Macitentan is an oral endothelin receptor antagonist (ERA) that selectively and irreversibly blocks both endothelin type A (ETA) and type B (ETB) receptors.
Physiological Effect: By inhibiting endothelin-1 binding, it prevents vasoconstriction, vascular remodeling, and smooth muscle cell proliferation in the pulmonary arteries.
4. Safety and Warnings
Pregnancy and Fetal Toxicity: Contraindicated during pregnancy due to teratogenic and embryotoxic effects. Female patients of reproductive potential must use two highly effective forms of contraception during treatment and for one month after discontinuation.
Hepatic Toxicity: Can cause liver injury. Liver function tests (LFTs) should be monitored before initiation and as clinically indicated.
Anemia: Hemoglobin and hematocrit levels may decrease, typically occurring within the first few months of therapy.
Edema: Peripheral edema and fluid retention may occur.
5. Adverse Reactions and Clinical Research
Most Common Adverse Reactions: Anemia, nasopharyngitis, headache, bronchitis, influenza, and urinary tract infection.
Clinical Research: Clinical trials have demonstrated improvements in six-minute walk distance and reduction in the composite risk of morbidity and mortality.
6. Drug Interactions
CYP3A4 Inhibitors: Strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) increase macitentan exposure and should be avoided.
CYP3A4 Inducers: Strong CYP3A4 inducers (e.g., rifampin) significantly decrease macitentan exposure and should be avoided.
CYP2C9 Inhibitors: Moderate inhibitors (e.g., fluconazole, amiodarone) may increase exposure and should generally be avoided.
7. Pharmaceutical Information
Chemical Composition: Active ingredient: Macitentan.
Appearance: White to off-white, oblong, film-coated tablets.
Storage: Store at controlled room temperature (20°C to 25°C). Protect from moisture.