Which one is more effective, macitentan (Aoposu) or ambrisentan?

Macitentan (macitentan) and ambrisentan (ambrisentan) are both endothelin receptor antagonists (ERA) and are mainly used to treat pulmonary arterial hypertension (PAH). The mechanism of action of the two is similar. They both inhibit vasoconstriction and vascular remodeling by blocking endothelin-1 receptors, thereby reducing pulmonary artery pressure and improving right heart function and exercise tolerance. However, there are certain differences in selectivity, half-life and clinical efficacy of drugs, which also affects the comparison of their effects in actual use.

Macitentan is a dual-receptor antagonist that acts on both the ETA receptor and the ETB receptor. Therefore, it can theoretically block endothelin-mediated vasoconstriction and proliferation signals more comprehensively. Its half-life is long and its blood concentration is stable. It is suitable for oral administration once a day and has good patient compliance. Clinical studies have shown that macitentan can significantly reduce pulmonary artery pressure, delay disease progression, and have a protective effect on mortality and clinical deterioration events in long-term use.

Ambrisentan is a selective ETA receptor antagonist and has a weak effect on ETB receptors, so it may retain a certain ETB mediated vasodilation and diuretic effect. Its daily dosage is flexible and can be adjusted based on patient tolerance. Clinical trials have shown that ambrisentan can improve 6 minute walking distance (6MWD), cardiac function classification and hemodynamic indicators, but some studies have shown that its long-term impact on mortality is slightly lower than macitentan.

Taken together, macitentan shows certain advantages in reducing pulmonary artery pressure and delaying disease progression, and is especially suitable for patients with moderate to severe PAH or those who want to reduce the risk of disease progression; while ambrisentan has a selective effect and relatively mild side effects, and is also suitable for patients with poor tolerance or early mild to moderate disease. The final drug selection should be based on the patient's condition, cardiac function status, liver and kidney function, drug availability and economic factors, and be decided by a specialist after individualized assessment.

Keyword tag:

Macitentan, Aoposil, pulmonary arterial hypertension,PAH, lifelong use, risk of discontinuation, doctor's advice, long-term management, disease control

Reference materials:https://go.drugbank.com/drugs/DB08932