Effectiveness and Safety of Prochlorperazine in Indian Patients with Acute Vertigo: Results from a Large, Prospective, Post-marketing Observational Study

AIM: To assess the efficacy and safety of prochlorperazine in Indian patients with acute vertigo. METHODS: In this prospective, multicenter, open-label, post-marketing observational study, patients with acute peripheral vertigo of different etiologies received 5 mg prochlorperazine thrice a day for 5 days. The primary endpoints were percentage of patients with improvement in (1) vertigo symptoms and (2) clinical response as per scale for vestibular vertigo severity level and clinical response evaluation (SVVSLCRE) from baseline to end of treatment (Day 6). The key secondary endpoints were (1) improvement in nystagmus grading, and (2) safety and tolerability Efficacy of prochlorperazine by route of administration of first prochlorperazine dose (oral or intramuscular) was also assessed. RESULTS: Of 1716 enrolled patients (mean [standard deviation, SD]) age (42.0 [12.95] years; 53.6% men), 57.4% were diagnosed with Meniere’s disease, followed by vestibular neuritis (17.4%), labyrinthitis (16.7%), or ear surgery (8.5%). In the overall population, 91.1% of patients showed improvement in clinical response per SVVSLCRE grading at Day 6 (p < 0.0001 vs. non-responders). Nystagmus grading was improved in 99.7% (of patients. No adverse drug reactions events were reported. Tolerability of prochlorperazine was rated as good, very good, and excellent by 43.6%, 32.9% and 20.7% of patients, respectively. Among patients with postoperative vertigo, 80.1% showed improvement in clinical response. In the intramuscular and oral subsets, 85.5% and 92.1% of patients showed improved clinical response, respectively. CONCLUSION: Prochlorperazine showed improvement in severity of symptoms and clinical response in all subsets of vertigo patients, with a good safety and tolerability profile. TRIAL REGISTRATION NUMBER: CTRI/2022/01/039287. DATE OF REGISTRATION: 10 January 2022.