Darusentan is an orally active, propanoic acid-based endothelin receptor antagonist (ERA) that selectively blocks endothelin-1 (ET-1) binding to the endothelin type-A (ETA) receptor. Darusentan exhibited subnanomolar binding affinity and approximately 1000-fold selectivity for the ETA receptor in binding experiments conducted in vitro under steady-state conditions. Darusentan is orally bioavailable and, when administered to humans, maximum plasma concentrations are observed within 1–2 h post dosing. The mean elimination half-life is relatively long (>15 h), which is consistent with once-daily dosing. Darusentan is primarily glucuronidated by Phase II enzymes in the liver, and the major route of elimination of Darusentan and its metabolites is via the bile. Some glucuronidated metabolites of Darusentan are also excreted in the urine. Darusentan doses up to 300 mg/day were well tolerated and associated with a manageable safety profile in patients with resistant hypertension (RHTN). The most frequently reported adverse events in Ddarusentan-treated subjects were peripheral edema (17%) and headache (11%), which were mostly mild or moderate in severity. Other commonly reported adverse events in the Darusentan treatment group were sinusitis (8%), dizziness (7%), upper respiratory tract infection (5%) and gastroenteritis (5%). In phase III clinical trial the mean reductions in clinic systolic and diastolic blood pressures were 9/5 mm Hg with placebo, 17/10 mm Hg with Darusentan 50 mg, 18/10 mm Hg with Darusentan 100 mg, and 18/11 mm Hg with Darusentan 300 mg. Unfortunately, phase III clinical trial evaluating Darusentan did not achieve its co-primary efficacy endpoints of achieving a change in systolic and diastolic blood pressure after 14 weeks compared to a placebo. Perhaps for this reason, shortly after the top-line results of this study became known, the sponsor announced that Darusentan would not be developed further for resistant hypertension.