Impact of Patient Subgroups on the Efficacy and Safety of Methylnaltrexone for Opioid-Induced Constipation in Patients with Advanced Illness.

Methylnaltrexone treatment was superior to placebo in achieving rescue-free laxation within 4 and 24 hours after the first dose, irrespective of patients' cancer status, baseline ECOG performance status, or baseline opioid or laxative use. The methylnaltrexone safety profile remained consistent across baseline characteristic subgroups.