Promethazine vs. Lorazepam for Treatment of Vertigo


This study was a prospective, randomized, double-blind, parallel group clinical trial designed to compare the efficacy of intravenous (IV) promethazine and lorazepam for the treatment of peripheral vertigo in Emergency Department setting.

Full Title of Study: “Promethazine vs. Lorazepam for Treatment of Vertigo in the Emergency Department: A Randomized Clinical Trial”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
  • Study Primary Completion Date: June 2013


  • Drug: Promethazine
  • Drug: Lorazepam

Arms, Groups and Cohorts

  • Active Comparator: Promethazine
    • IV promethazine (25 mg)
  • Active Comparator: lorazepam
    • IV lorazepam (2 mg)

Clinical Trial Outcome Measures

Primary Measures

  • Mean change in vertigo intensity.
    • Time Frame: At 2 hours after intervention.
    • The primary efficacy outcome was the mean change in the vertigo intensity score between pre- and post-intervention at 2 hours after administration of study medications.

Secondary Measures

  • Efficacy and Safety outcome measures (nausea change-second dose-adverse events).
    • Time Frame: At 2-8 hours after intervention.
    • Secondary outcomes included, mean change in nausea VAS score, need for second dose of study medications, and the rate of drug-related adverse events for the subjects in each study group after intervention.

Participating in This Clinical Trial

Inclusion Criteria

  • Aged 18 years or older – Background history of positional vertigo Exclusion Criteria:

  • Unable to provide informed consent – Pregnant or possibly pregnant – Known allergy to study medications – Use of antiemetic agents in the previous 24 hours – Evidence of drug-induced vertigo or orthostatic hypotension – Central pathologies/central origin for vertigo

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 65 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Shahid Beheshti University of Medical Sciences
  • Provider of Information About this Clinical Study
    • Principal Investigator: Shadi Asadollahi, Research Assistant – Shahid Beheshti University of Medical Sciences

Clinical trials entries are delivered from the US National Institutes of Health and are not reviewed separately by this site. Please see the identifier information above for retrieving further details from the government database.

At, we keep tabs on over 200,000 clinical trials in the US and abroad, using medical data supplied directly by the US National Institutes of Health. Please see the About and Contact page for details.