Orlistat Probably Doesn't Cause Acute Liver Injury

Excess risk for liver injury was present for 90 days before and after first orlistat prescription.

Orlistat (Alli; Xenical), which inhibits gastric and pancreatic lipase and prevents some dietary fat absorption, is one of only a few drugs available for treating obesity. In 2009, the FDA issued a warning about possible association between orlistat use and liver injury. In this population-based study, U.K. investigators used several large databases to assess this possible connection.

During a mean observation period of 9 years, 95,000 patients received at least one prescription for orlistat (median age at first prescription, 48; mean duration of orlistat treatment, 11 months). During the observation period, about 1000 patients suffered "definite" or "probable" idiopathic liver injury; 94 patients experienced liver injury during orlistat treatment. Compared with periods of nonuse, the first 30 days of orlistat use were associated with significant excess risk for liver injury (incidence rate ratio, 2.2); no excess risk was noted after 30 days of use. Risk for liver injury was also higher during the 90 days before orlistat use (IRR, 1.5). Notably, risks during the 90 days before and during the 90 days after first orlistat use were similar. When only definite cases were considered, excess risk for liver injury was present during the 90 days before orlistat prescription (IRR, 1.8), but not during orlistat use.

CITATION(S):

Douglas IJ et al. Orlistat and the risk of acute liver injury: Self controlled case series study in UK Clinical Practice Research Datalink. BMJ 2013 Apr 12; 346:f1936.