Comparison of efficacy dimenhydrinate and metoclopramide in the treatment of nausea due to vertigo; a randomized study.

Background: This study aimed to compare the therapeutic efficacy of dimenhydrinate and metoclopramide in patients with nausea and vertigo.

Methods: A prospective, double-blind, randomized clinical trial was performed on patients who presented to the emergency department (ED) with nausea and vertigo in the six month period between Nov 1st 2012 and May 1st 2013. Adult patients who were 18 to 65 years old presenting to the ED with nausea and vertigo or motion sickness were included in the study. A total of 200 patients were divided into 2 groups who were admitted to ED with complaints of vertigo accompanied by nausea. In the first group, 50 mg dimenhydrinate and 10 mg metoclopramide infusions were given intravenously for 15 min. The efficacy of treatment was measured by using a 10 mm Visual Analog Scale (VAS) performed at 0, 15 and the 30th minute. The primary outcome variable was a reduction in vertigo intensity documented on the VAS at the 30th minute after medication administration.

Results: A total of 200 patients were included in the randomization (n=100 in both groups). The baseline vertigo VAS scores were 7.57±1.42 in the dimenhydrinate (DMT) group and 7.27±1.40 in the metoclopramide (MTP) group (p=0.09). In the 30th minute of treatment, the average vertigo VAS score was 2.46 ± 2.39 in the DMT group and 2.31±1.96 in the MTP group; no significant differences were detected between groups. The baseline nausea VAS scores were 7.62±1.48 in the DMT group and 7.45±1.27 in the MTP group (p=0.36). In the 30th minute of treatment the average vertigo VAS score decreased to 2.27±2.24 in the DMT group and 2.70±2.48 in the MTP group, no significant differences were detected between groups. No significant differences were detected between nausea VAS changes and vertigo VAS changes at 30th minutes of the treatment (p=0.06, p=0.85 respectively). Rescue medication need was similar in both treatment groups (p=0.94). No significant differences were detected about the side effects which are sedation (p=0.56) and hypotension (p=0.57).

Conclusions: In conclusion, this prospective, double-blind, randomized study showed that both DMT and MTP have similar efficacy in reducing nausea and vertigo symptoms in the ED.