Evaluation of the neuroprotective effect of dextromethorphan in the acute phase of ischaemic stroke

Introduction: Stroke is the second leading cause of death in the world. However, there is still no approved neuroprotective drug for acute ischaemic stroke. To clarify the neuroprotective efficacy and safety of dextromethorphan in stroke, the following study was carried out. Material and methods: Forty patients with acute stroke causing moderate deficit were randomized to be treated with either dextromethorphan 300 mg per day or placebo for 5 days. Plasma level of dextromethorphan and its active metabolite was not evaluated in this study. The NIHSS score was calculated on day 5 and the Barthel activities of daily living index and Rankin score were checked after 3 months by a blinded investigator. Collected data were analysed using the t-test and chi(2) test. Results: In the dextromethorphan-treated group, the mean NIHSS score was 16.8 +/- 3.9 at baseline, and was 14.2 +/- 4.8 for the placebo-treated group (p = 0.069). At day 5, there was also no significant difference regarding NIHSS score (p = 0.167). At the 3-month follow-up, there was no significant difference regarding Barthel scale and Rankin score between the dextromethorphan and placebo groups. Conclusions: The results of our study suggest that although low-dose and short-term oral administration of dextromethorphan seems to be not neuroprotective, it does not worsen either patients' condition or NIHSS score. Moreover, patients treated with dextromethorphan showed a significant reduction in seizures (complication after stroke), but had increased chance of MI and renal failure by almost 5% when compared to the placebo-treated groups. More prolonged studies with a higher number of cases are recommended.