What is the preferred medication, Unisom (doxylamine) or Benadryl (diphenhydramine), for a patient taking a red-eye flight?

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From the FDA Drug Label

Warnings Do not use • to make a child sleepy• with any other product containing diphenhydramine, even one used on skin Ask a doctor before use if you have • a breathing problem such as chronic bronchitis• glaucoma• trouble urinating due to enlarged prostate gland When using this product • marked drowsiness may occur• avoid alcoholic drinks• alcohol, sedatives, and traquilizers may increase drowsiness• be careful when driving a motor vehicle or operating machinery• excitability may occur, especially in children Principal Display Panel Walgreens WALGREENS PHARMACIST RECOMMENDED Compare to the active ingredient in Unisom® SleepTabs® Sleep Aid DOXYLAMINE SUCCINATE TABLETS, 25 mg / NIGHTTIME SLEEP AID Nighttime • Clinically tested, proven effective

Unisom (doxylamine) and Benadryl (diphenhydramine) are both used as sleep aids.

  • Key differences:
    • Unisom is specifically marketed as a nighttime sleep aid 1.
    • Benadryl has warnings against using it to make a child sleepy and has several precautions, such as avoiding use with sedatives or tranquilizers, and being careful when driving or operating machinery 2. Given the context of a redeye flight, neither medication is ideal as both can cause marked drowsiness and may impair ability to drive or operate machinery after the flight. However, Unisom (doxylamine) might be a slightly better choice for a redeye flight due to its specific marketing as a nighttime sleep aid 1.

From the Research

Unisom (doxylamine succinate) is generally the better choice for helping with sleep during a redeye flight compared to Benadryl (diphenhydramine) due to its slightly longer duration of action and less next-day grogginess. When considering the use of Unisom or Benadryl for sleep during a redeye flight, it's essential to weigh the benefits and risks of each medication.

  • Unisom tends to have a longer duration of action (6-8 hours) compared to Benadryl (4-6 hours), making it more suitable for overnight flights 3.
  • Both medications work by blocking histamine receptors in the brain, which promotes drowsiness, but Unisom is specifically marketed as a sleep aid while Benadryl is primarily an antihistamine.
  • Side effects for both can include dry mouth, blurred vision, and urinary retention, as noted in a study on the use of over-the-counter sleep aids among older adults 4.
  • It's crucial to avoid alcohol when taking either medication as this can intensify drowsiness and side effects.
  • If you have glaucoma, prostate problems, or certain heart conditions, consult with a healthcare provider before using either medication.
  • For the best results, also consider wearing an eye mask, using earplugs, and avoiding caffeine and screens before attempting to sleep. A study comparing the effects of diphenhydramine and modafinil on arousal and autonomic functions in healthy volunteers found that diphenhydramine had sedative effects, while modafinil had alerting effects 5. However, the most recent and highest quality study on the topic of anticholinergic use, including diphenhydramine, highlights the importance of careful consideration of the evidence for efficacy and the risks for serious adverse events 6. Given the potential risks and benefits, Unisom is recommended at a dose of 25mg taken about 30 minutes before you want to fall asleep, but it's essential to consult with a healthcare provider before using either medication, especially if you have any underlying medical conditions.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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