Products
Ambrisentan is commercially available in the form of film-coated tablets (Volibris). It has been approved in many countries since 2008. Generic versions were registered in 2020.
Structure and properties
Ambrisentan (C22H22N2O4, Mr = 378.4 g/mol) is a dimethylpyrimidine, diphenyl and propionic acid derivative and exists as a white crystalline powder that is practically insoluble in water.
Effects
Ambrisentan (ATC C02KX02) is a selective antagonist at the ETA receptor, which is primarily responsible for vasoconstriction and cell proliferation triggered by endothelin. Unlike bosentan (Tracleer), it does not bind to the ETB receptor, so it is not a dual antagonist.
Indications
For the treatment of pulmonary arterial hypertension.
Dosage
According to the SmPC. Tablets are taken once daily, regardless of meals.
Contraindications
- Hypersensitivity
- Pregnancy
- Impaired liver function
- Liver enzyme elevations
- Idiopathic pulmonary fibrosis with or without secondary pulmonary hypertension.
Full details of precautions and interactions can be found in the drug label.
Interactions
Unlike bosentan, ambrisentan is mainly glucuronidated and is metabolized by CYP450 to only a minor extent.
Adverse effects
The most common potential adverse effects include headache, peripheral edema, and fluid retention. Ambrisentan may have potential for hepatoxic side effects. Therefore, liver enzymes should be checked regularly during treatment.
