ZQuil (Diphenhydramine) Should Not Be Used for Chronic Insomnia
Do not use ZQuil (diphenhydramine) for chronic insomnia—the VA/DOD guidelines explicitly recommend against it, and you should instead prioritize cognitive behavioral therapy for insomnia (CBT-I) as first-line treatment. 1
Why Diphenhydramine Is Not Recommended
The 2020 VA/DOD Clinical Practice Guidelines make a clear "weak against" recommendation for diphenhydramine in chronic insomnia disorder. 1 This recommendation is based on:
- Lack of efficacy data supporting its use for chronic insomnia 2
- Significant safety concerns, particularly anticholinergic effects causing confusion, urinary retention, and increased fall risk 3
- Daytime sedation that impairs cognitive and psychomotor function 2
- Delirium risk, especially in elderly patients and those with advanced illness 2
The American Academy of Sleep Medicine explicitly states that over-the-counter antihistamines like diphenhydramine are not recommended due to these safety concerns and lack of supporting evidence. 2
What You Should Do Instead
First-Line Treatment: CBT-I
Start with Cognitive Behavioral Therapy for Insomnia (CBT-I) before any medication. 1 This is a strong recommendation from the VA/DOD guidelines and provides superior long-term outcomes compared to pharmacotherapy. 1
CBT-I includes:
- Stimulus control therapy (associating bed with sleep only) 2
- Sleep restriction therapy (limiting time in bed to actual sleep time) 2
- Cognitive restructuring (addressing maladaptive thoughts about sleep) 2
- Sleep hygiene education (though insufficient as monotherapy) 1
CBT-I can be delivered through individual therapy, group sessions, telephone-based programs, web-based modules, or self-help books—all formats show effectiveness. 2
If Pharmacotherapy Is Needed
Only add medication if CBT-I is insufficient or unavailable, and use it to supplement—not replace—behavioral interventions. 2
For short-course pharmacotherapy, the VA/DOD guidelines suggest:
For sleep onset and maintenance insomnia:
- Eszopiclone 2-3 mg (weak for recommendation) 1, 2
- Zolpidem 10 mg (5 mg in elderly) (weak for recommendation) 1, 2
- Temazepam 15 mg (weak for recommendation) 1
For sleep onset insomnia specifically:
- Zaleplon 10 mg (weak for recommendation) 1, 2
- Ramelteon 8 mg (insufficient evidence, but considered) 1, 2
For sleep maintenance insomnia:
- Low-dose doxepin 3-6 mg (weak for recommendation) 1, 2
- Suvorexant (orexin receptor antagonist) (weak for recommendation) 1, 4
Critical Safety Considerations
All hypnotics carry risks including:
- Complex sleep behaviors (sleep-driving, sleep-walking) 2
- Falls and fractures, particularly in elderly patients 2, 5
- Cognitive impairment and daytime sedation 2
- Driving impairment 2
Use the lowest effective dose for the shortest duration possible. 2 Reassess after 1-2 weeks to evaluate efficacy and monitor for adverse effects. 2
Common Pitfalls to Avoid
- Using OTC antihistamines like diphenhydramine because they're easily accessible—they lack efficacy data and have problematic anticholinergic effects 2, 3
- Prescribing medication without implementing CBT-I—behavioral interventions provide more sustained effects than medication alone 2
- Continuing pharmacotherapy long-term without periodic reassessment 2
- Failing to screen for underlying sleep disorders (sleep apnea, restless legs syndrome) if insomnia persists beyond 7-10 days of treatment 2
Special Considerations for Elderly Patients
Elderly patients require:
- Lower doses (e.g., zolpidem maximum 5 mg) due to increased sensitivity 2
- Extra caution with all sedative-hypnotics due to higher risk of falls, cognitive impairment, and complex sleep behaviors 2
- Avoidance of diphenhydramine specifically due to strong anticholinergic effects causing confusion and urinary retention 3