What is the role of intravenous (IV) Benadryl (diphenhydramine) in the treatment of migraines?

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From the Guidelines

Intravenous (IV) Benadryl (diphenhydramine) is not a recommended first-line treatment for migraines, and its use should be considered on a case-by-case basis, particularly in emergency department settings where other treatments have failed or are contraindicated. The typical dose is 25-50 mg administered intravenously, often in combination with other medications such as IV metoclopramide, prochlorperazine, or pain medications. According to the most recent guidelines 1, the recommended first-line treatments for acute migraine attacks include eletriptan, frovatriptan, rizatriptan, sumatriptan, and zolmitriptan, as well as aspirin-acetaminophen-caffeine.

Some key points to consider when using IV Benadryl for migraines include:

  • Its ability to counteract side effects of other migraine medications, such as akathisia from antiemetics
  • Its provision of mild sedation to help patients rest during an attack
  • Its potential direct analgesic properties
  • Its antihistamine properties, which may help reduce inflammation associated with migraine pathophysiology
  • Common side effects, including drowsiness, dry mouth, and occasionally paradoxical excitation

It's essential to note that IV Benadryl is not FDA-approved specifically for migraine treatment, and its use is considered off-label. However, in emergency settings where first-line treatments are ineffective or contraindicated, IV Benadryl may be considered as an adjunctive treatment, as suggested by older studies 1. Nevertheless, the most recent and highest-quality evidence 1 should guide treatment decisions, prioritizing recommended first-line therapies and reserving IV Benadryl for specific cases where its benefits outweigh the risks.

From the Research

Role of IV Benadryl in Migraine Treatment

  • IV Benadryl (diphenhydramine) is not typically considered a first-line treatment for migraines, but it may be used as an adjunct therapy 2.
  • In one study, IV diphenhydramine was administered in combination with prochlorperazine or metoclopramide for the treatment of acute migraine, and both combinations were found to be efficacious 2.
  • However, there is limited evidence to support the use of IV Benadryl as a standalone treatment for migraines, and its effectiveness and safety in this context are not well established 3, 4, 5.
  • Other medications, such as metoclopramide, prochlorperazine, and sumatriptan, have more robust evidence supporting their use as first-line treatments for migraines 4, 6.
  • The American Headache Society recommends using injectable non-steroidal anti-inflammatory drugs (NSAIDs) or acetaminophen as second-line treatments for migraines, but does not mention IV Benadryl as a recommended treatment 3.

Key Findings

  • A study published in 2008 found that IV prochlorperazine and metoclopramide, both combined with IV diphenhydramine, were effective treatments for acute migraine 2.
  • A 2016 guideline from the American Headache Society recommends using metoclopramide, prochlorperazine, and sumatriptan as first-line treatments for migraines, but does not mention IV Benadryl 4.
  • A 2024 systematic review and Bayesian network meta-analysis found that chlorpromazine IV/IM was the most likely to be superior for adequate pain relief at 2 hours, but did not evaluate IV Benadryl as a treatment option 5.

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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