Diphenhydramine, Sodium Bicarbonate, or Combination for Acute Peripheral Vertigo: A Randomized Clinical Trial

Area of Science:

• Emergency Medicine
• Neurology
• Pharmacology

Background:

• Intravenous diphenhydramine is a common treatment for acute peripheral vertigo, but its sedative side effects are a concern.
• Sodium bicarbonate is an alternative therapy used in Eastern countries for vertigo, potentially offering relief without sedation.
• Limited comparative evidence exists for the efficacy and safety of diphenhydramine versus sodium bicarbonate in treating acute peripheral vertigo.

Purpose of the Study:

• To evaluate and compare the efficacy and safety of intravenous diphenhydramine, sodium bicarbonate, and their combination in emergency department patients with acute peripheral vertigo.

Main Methods:

• A triple-arm, double-blind, randomized clinical trial involving 222 adult patients with acute peripheral vertigo.
• Patients received either intravenous diphenhydramine, sodium bicarbonate, or a combination of both.
• The primary outcome was the change in vertigo severity measured by a visual analog scale (VAS) at 60 minutes post-treatment.

Main Results:

• Combination therapy demonstrated significantly greater improvement in vertigo severity compared to diphenhydramine alone (P=.01).
• Sodium bicarbonate showed similar vertigo improvement to diphenhydramine (P=.34) but with significantly less lethargy (P<.001).
• The combination group required less rescue medication (17.8%) compared to the diphenhydramine group (46.7%; P<.001).

Conclusions:

• Combination therapy of diphenhydramine and sodium bicarbonate offers superior symptom relief for acute peripheral vertigo compared to diphenhydramine monotherapy.
• Sodium bicarbonate is a viable alternative, providing comparable vertigo relief to diphenhydramine with a reduced risk of sedation.
• Further research is recommended to identify specific peripheral vertigo subtypes that benefit most from sodium bicarbonate and to elucidate its mechanisms of action.