Orlistat: should we worry about liver inflammation?

In a linked paper (doi:10.1136/bmj.f1936), Douglas and colleagues used data from the UK Clinical Practice Research Datalink and Hospital Episodes Statistics to explore the possible association between orlistat use and abnormalities of liver function in 94 695 patients who received orlistat over a 12 year period.1 Orlistat is an inhibitor of intestinal and pancreatic lipases that was first licensed for the treatment of overweight and obesity in 2008 and became available in the United Kingdom in 2009. It is currently the only prescription drug available for the treatment of obesity and is also available over the counter in a lower strength form, with slightly reduced efficacy. The drug acts within the gastrointestinal tract and less than 1% is absorbed systemically. As a result, circulating concentrations of orlistat are low (<0.02 μmol/L), and at this concentration it has no systemic effects on other lipases.

A meta-analysis of more than 10 000 patients in clinical trials showed a mean placebo subtracted weight loss of 2.9 kg over 12 months of treatment.2 Weight loss was maintained long term for subjects in one study, as long …