According to Healio, the antihistamine diphenhydramine HCI can provide rapid sleep onset and improve other issues related to occasional sleeplessness.

“For years, sleep studies have been conducted on people who report chronic insomnia, leaving us to assume that popular sleep aids containing diphenhydramine (DPH) are also effective in those who only have trouble falling asleep from time to time,” Andrew N. Carr, PhD, a clinical scientist for Procter & Gamble and study coauthor, said in an interview. “This research is the first time the compound has been studied in a population of people suffering from occasional sleeplessness and it shows the power of the medication.”

To determine the efficacy of DPH HCI in helping patients with occasional sleeplessness, Carr and colleagues conducted a 4-week, randomized, crossover, double-blind, placebo-controlled, in-home study. The 33 participants self-administered the sleep aide ZzzQuil (Procter & Gamble), in which the active ingredient is DPH HCI 50 mg.

The researchers assessed sleep parameters using ZEO Sleep Manager, Actiwatch 2 and the participants’ completed questionnaires. Occasional sleeplessness was verified with a 7-day baseline period sleep diary. Participants took the treatment as-needed for the first 7 nights of the study, followed by 2 mandatory nights. A period of no treatment lasting at least 5 days occurred between treatments. Of the participants, 22 completed the study and were able to be evaluated.

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