Alosetron is a 5-HT3 antagonist used for the management of severe diarrhoea-predominant irritable bowel syndrome (IBS) in women only. It was withdrawn from the market in 2000 owing to the occurrence of serious life-threatening gastrointestinal adverse effects, but was reintroduced in 2002 with availability and use restricted. It is currently marketed by GlaxoSmithKline under the trade name Lotronex.