The association between zolpidem and infection in patients with sleep disturbance

Objective: Recent case reports suggest that zolpidem usage may be associated with infection events. The aim of this study was to determine the risk of infection events in patients with sleep disturbance taking zolpidem in a full 3-year follow-up study. Methods: A total of 17474 subjects with a diagnosis of sleep disturbance in 2002 and 2003 were identified, of whom 5882 had used zolpidem after recruitment. A Cox proportional hazard model was used to estimate the 3-year infection event-free rates for the patients using zolpidem and those not using zolpidem after adjusting for confounding factors. To maximize case ascertainment, only patients hospitalized for infection events were included. Results: A total of 646 patients had had infection events, 331 (5.63%) of whom had been taking zolpidem and 315 (2.71%) had not. Zolpidem usage increased the risk of infection events. After adjustments for gender, age, co-morbidities, and other medications, patients using zolpidem with cDDD 1-28, 29-84, and >84 had hazard ratios of 1.67 (95% CI, 1.32e2.11), 1.91 (95% CI, 1.47e2.49) and 1.62 (95% CI, 1.32e1.98) respectively, compared with patients who did not use zolpidem. Conclusions: Zolpidem increased the risk of infection events in sleep disturbance patients. This increased risk of infection should be explained to sleep disturbance patients, and prescriptions of zolpidem to chronic insomnia patients should be restricted.