Study objectives: Although difficulty maintaining sleep (DMS) is the most common nighttime insomnia symptom among US adults, many FDA-approved hypnotics have indications only for sleep onset, stipulating bedtime administration to offset residual sedation. Given the well-known self-medication tendencies of insomniacs, concern arises that maintenance insomniacs might be prone to self-administer their prescribed hypnotics middle-of-the-night (MOTN) after nocturnal awakenings, despite little efficacy-safety data supporting such use. However, no US data characterize the actual population prevalence or correlates of MOTN hypnotic use.
Methods: Telephone interviews assessed patterns of prescription hypnotic use in a national sample of 1,927 commercial health plan members (ages 18-64) receiving prescription hypnotics within 12 months of study. The Brief Insomnia Questionnaire assessed insomnia symptoms.
Results: 20.2% of respondents reported MOTN hypnotic use, including 9.0% who sometimes used twice-per-night (once at bedtime plus once MOTN) and another 11.2% who sometimes used MOTN, but never twice-per-night. The remaining 79.8% used exclusively at bedtime. Among exclusive MOTN users, only 14.0% used MOTN on the advice of their physician (52.6% of those seen by sleep medicine specialists and 42.6% by psychiatrists vs. 5.2% to 13.6% seen by other physicians). MOTN use predictors included DMS being the most bothersome sleep problem, long duration of hypnotic use, and low frequency of DMS.
Conclusions: One-fifth of patients with prescription hypnotics used MOTN, only a minority on advice from their physicians. Since significant next-day cognitive and psychomotor impairment is documented with off-label MOTN hypnotic use, prescribing physicians should question patients about unsupervised MOTN dosing.
Keywords: Insomnia; dosing; hypnotics; medication adherence; middle-of-the-night; prevalence; sleep maintenance.