Sitaxentan-related acute liver failure in a patient with pulmonary arterial hypertension.

Liver toxicity is a well recognised side-effect of endothelin receptor antagonists (ERAs) (bosentan, sitaxentan and ambrisentan) and long-term monthly monitoring of liver function tests (LFTs) is mandatory. Sitaxentan is thought to be less commonly associated with liver toxicity compared with the older agent bosentan and has been used as an alternative in patients who develop liver dysfunction on bosentan [1–3]. However, several recently published cases of sitaxentan-related liver injury have raised concerns that the potential of sitaxentan to cause serious liver toxicity has been underestimated. To date , there are six such cases reported in the medical literature, including two deaths (one patient was on a higher dose of 300 mg twice daily in the pre-marketing stage and the other patient died from pneumonia 2 months after drug withdrawal) and one patient requiring liver transplantation (patient was also on another potentially hepatotoxic drug) [4–6]. We would like to report a case of a young patient with idiopathic pulmonary arterial hypertension (IPAH) who developed acute liver failure while taking sitaxentan. Her LFTs had always been and were normal, last tested 1 month before the development of acute liver failure, which was within the timescale of the LFT monitoring procedure currently recommended.