Ambrisentan is a medication primarily used for the treatment of pulmonary arterial hypertension (PAH). It belongs to a class of drugs called selective endothelin receptor A (ETA) antagonists. By blocking the binding of endothelin-1 (ET-1) to the ETA receptor, Ambrisentan reduces pulmonary arterial pressure and resistance, thereby improving symptoms and exercise tolerance in patients with PAH.
I. Basic Information
Chemical Name: (+)-(2R,3aS,7aS)-2-((S)-2-((tert-Butyldimethylsilyl)oxy)-3-(4-methoxyphenyl)propanamido)-7a-(2-propynyl)octahydroindole-2-carboxylic acid ethyl ester
CAS Number: 177435-19-5
Molecular Formula: C30H44N2O5Si
Molecular Weight: 544.76
II. Pharmacological Action
As a selective ETA antagonist, Ambrisentan exerts its effects through the following mechanisms:
Blocking ET-1 Binding to ETA Receptors: ET-1 is a potent vasoconstrictor and stimulator of smooth muscle cell proliferation, playing a crucial role in the pathogenesis of PAH. Ambrisentan inhibits ET-1's vasoconstrictive and proliferative effects by blocking its binding to ETA receptors.
Reducing Pulmonary Arterial Pressure and Resistance: By inhibiting ET-1, Ambrisentan lowers pulmonary arterial pressure and resistance, improving hemodynamic status in patients with PAH.
Improving Exercise Tolerance and Symptoms: With reduced pulmonary arterial pressure and resistance, patients experience improved exercise tolerance and alleviation of symptoms, leading to an enhanced quality of life.
III. Indications
Ambrisentan is indicated for the treatment of patients with PAH (WHO Group 1) who have WHO Class II or III symptoms, to improve exercise capacity and delay clinical worsening. It may also be used in combination with other therapeutic agents to further enhance efficacy.
