Diphenhydramine in sleep aid
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Diphenhydramine as a Sleep Aid: Efficacy, Safety, and Usage
Introduction to Diphenhydramine in Sleep Aids
Diphenhydramine, a first-generation antihistamine, is commonly used as an over-the-counter (OTC) sleep aid due to its sedative properties. It is often self-administered by individuals experiencing mild to moderate insomnia. This article synthesizes research findings on the efficacy, safety, and usage patterns of diphenhydramine as a sleep aid.
Efficacy of Diphenhydramine in Treating Insomnia
Improvements in Sleep Parameters
Several studies have demonstrated that diphenhydramine can improve various sleep parameters. In a double-blind, placebo-controlled study involving mildly to moderately insomniac patients, diphenhydramine significantly reduced sleep latency and increased sleep efficiency compared to placebo1 3. Another study found that diphenhydramine was effective in reducing sleep latency and the number of awakenings per night in pediatric patients4.
Subjective Sleep Quality
Patients using diphenhydramine reported feeling more restful the following morning and preferred the drug over placebo despite experiencing more side effects3. Additionally, a study comparing diphenhydramine with a valerian-hops combination found that both treatments produced modest improvements in subjective sleep parameters, with diphenhydramine showing significant increases in sleep efficiency during the first 14 days of treatment1.
Safety and Side Effects of Diphenhydramine
Next-Day Residual Effects
One of the concerns with diphenhydramine is its next-day residual sedative effect. A study using positron emission tomography (PET) to measure brain H1 receptor occupancy found significant residual sedative effects the morning after nighttime administration of diphenhydramine2. This hangover effect necessitates caution, especially in activities requiring alertness the next day.
Adverse Effects in Older Adults
Older adults are particularly vulnerable to the adverse effects of diphenhydramine. Studies have shown that older adults using diphenhydramine are at risk of daytime sedation, compromised cognitive function, and falls5 9. The 2015 Beers Criteria recommend that individuals aged 65 and older avoid using diphenhydramine due to these potential risks5.
Usage Patterns and Public Health Concerns
Prevalence of Use
Diphenhydramine is widely used as an OTC sleep aid. A study among the Saudi population found that 87.2% of respondents had previously used medications containing diphenhydramine, with 31.9% currently using them6. The most common reason for use was insomnia, and younger female students were the majority of users6.
Inappropriate Use in Older Adults
A significant proportion of older adults use diphenhydramine-containing products despite the associated risks. More than half of the older adults in a study sample had used potentially inappropriate OTC medications containing diphenhydramine to improve sleep within the past 30 days5. This highlights the need for better awareness and consultation with healthcare providers to ensure safe use.
Conclusion
Diphenhydramine is an effective OTC sleep aid for reducing sleep latency and improving sleep efficiency in individuals with mild to moderate insomnia. However, its use is associated with next-day residual effects and potential risks, particularly in older adults. Awareness of these risks and appropriate consultation with healthcare providers are essential to ensure safe and effective use of diphenhydramine as a sleep aid.
Sources and full results
Most relevant research papers on this topic
Valerian-hops combination and diphenhydramine for treating insomnia: a randomized placebo-controlled clinical trial.
A valerian-hops combination and diphenhydramine both show modest hypnotic effects and improve sleep quality and quality of life for mild insomnia patients, with no rebound insomnia after discontinuation.
RCT
Highly CitedNext-Day Residual Sedative Effect After Nighttime Administration of an Over-the-Counter Antihistamine Sleep Aid, Diphenhydramine, Measured by Positron Emission Tomography
The next-day residual sedative effect of diphenhydramine, an over-the-counter sleep aid, was confirmed by PET measurement, highlighting the need for caution during their administration.
RCTDiphenhydramine in Insomniac Family Practice Patients: A Double‐Blind Study
Diphenhydramine, 50 mg at bedtime, significantly improves sleep parameters and restfulness in mild to moderate insomniac patients, with patients preferring it over placebo despite more side effects.
RCTHighly CitedThe Effectiveness of Diphenhydramine HCI In Pediatric Sleep Disorders
Diphenhydramine HCI is a safe and effective bedtime sleep aid for children with sleep disorders, reducing sleep latency time and number of awakenings without significantly impacting other study parameters.
RCTHighly CitedOver-the-counter medications containing diphenhydramine and doxylamine used by older adults to improve sleep
Most older adults in a limited sample in the United States are taking over-the-counter sleep medications containing diphenhydramine or doxylamine, which are potentially inappropriate for them.
Observational StudyThe Use of Over-the-Counter Sleep Aid Containing Diphenhydramine Hydrochloride Among Saudis
Over-the-counter sleep aids containing diphenhydramine hydrochloride are widely prevalent among Saudis, with younger female students being the majority of users.
Observational Study
Rigorous JournalA Systematic Review of the Efficacy and Safety of Over-the-Counter Medications Used in Older People for the Treatment of Primary insomnia.
Diphenhydramine and melatonin show potential in improving sleep measures in older people with primary insomnia, but more studies are needed in this population.
Systematic ReviewOver-the-Counter Agents for the Treatment of Occasional Disturbed Sleep or Transient Insomnia: A Systematic Review of Efficacy and Safety.
Common over-the-counter sleep-aid agents, especially diphenhydramine and valerian, lack robust clinical evidence supporting efficacy and safety for occasional disturbed sleep or transient insomnia.
Systematic ReviewSleep Health and Appropriate Use of OTC Sleep Aids in Older Adults—Recommendations of a Gerontological Society of America Workgroup
Older adults are more likely to use OTC sleep aids inappropriately, posing risks like daytime sedation and cognitive decline.
Rigorous JournalA Systematic Review of the Efficacy and Safety of Over-the-Counter Medications Used in Older People for the Treatment of Primary insomnia.
Diphenhydramine and melatonin show potential in improving sleep measures in older people with primary insomnia, but more studies are needed.
Systematic Review