Objective: To evaluate the impact of caffeine in medication on sleep complaints in a community population of persons aged 67 or older.
Design: Cross-sectional analysis.
Setting: Iowa 65+ Rural Health Study.
Participants: Those who completed their own interview, including a section on the use of medications, during the third annual in-person follow-up in 1984-1985.
Main outcomes: trouble falling asleep or other sleep complaints. Covariates: use of caffeine-containing medication, spasmolytic, or sympathomimetic drug; number of drugs used; depressive symptoms; self-perceived health; comorbidity, hip fracture, arthritis, ulcer of stomach or intestines; and consumption of caffeinated beverages.
Results: The prevalence of caffeinated medication use by participants was 5.4%. Those reporting the use of any caffeine-containing medication were at an increased risk of having trouble falling asleep (Odds Ratio [OR] = 1.79, 95% confidence interval [CI] = 1.19-2.68). There was no significant risk of other reported nighttime or daytime sleep problems associated with use of caffeine-containing drugs. Even after adjusting for other factors that could interfere with initiation of sleep, such as painful disease, depressive symptoms, polypharmacy, use of specific medications known to interfere with sleep, and coffee consumption, the use of caffeine-containing medication still presented a significantly increased risk of having trouble falling asleep (OR = 1.60, CI = 1.04-2.46). Although those participants using over-the-counter analgesic medication containing caffeine had an increased risk of trouble falling asleep (OR = 1.88, CI = 1.22-2.90), there was no significant risk of trouble falling asleep for those who took similar noncaffeinated OTC analgesic drugs (OR = 1.26, CI = 0.87-1.83).
Conclusions: The use of caffeine-containing medication is associated with sleep problems. Healthcare providers should be aware of potential problems associated with over-the-counter medications containing caffeine and should counsel patients about the potential of sleep problems. Older patients should be encouraged to read the label on medications and to select drugs that are caffeine-free when that is possible.