I de to studier med patienter med fingersår var forekomsten af forhøjede leveraminotransferaser (> 3 x ULN) 11, 3% hos patienter behandlet med bosentan (N = 168) sammenlignet med 0, 8% hos patienter behandlet med placebo (N = 129).
In the two studies in patients with digital ulcers the incidence of elevated liver aminotransferases (> 3 × ULN) was 11.3% in bosentan-treated patients (N = 168) compared with 0.8% in placebo-treated patients (N = 1 29).