Products
Sitaxentan had been on the market in the EU since 2006 in the form of film-coated tablets (Thelin 100 mg, Pfizer). It was withdrawn from the market in 2010 because of liver-toxic side effects.
Structure and properties
Sitaxentan (C18H15ClN2O6S2, Mr = 454.9 g/mol) is an oxazole, thiophene, benzodioxole, and sulfonamide derivative. It is present in drugs as sitaxentan sodium and is also known as sitaxsentan.
Effects
Sitaxentan (ATC C02KX03) is an anatonist of endothelin-1 (ET-1) at the endothelin receptor. It reverses the effects of the hormone, dilates blood vessels, lowers blood pressure, and improves symptomatology. Sitaxentan, unlike bosentan (Tracleer), is selective for the ETA receptor.
Indications
For the treatment of pulmonary arterial hypertension.
Adverse effects
The most common possible adverse effects include headache. Sitaxentan has hepatoxic properties. As a result of two fatal liver events during treatment, Pfizer voluntarily withdrew the drug from the market and stopped all clinical trials.