Ondansetron versus Amitriptyline in the Treatment of Peripheral Neuropathy: A Randomized Double Blind Prospective Clinical Study

Background and Objective: Clinical trials have shown the potential use of 5-HT3 receptor antagonists like Ondansetron, Tropisetron and Zacopride in a number of disorders of gastrointestinal tract and the central nervous system such as cancer chemotherapy induced vomiting, anxiety, depression, schizophrenia and migraine. Various experimental and clinical studies also point the usefulness of Ondansetron in neuropathic pain. Therefore, the present study was conducted to find out whether Ondansetron could be used as an alternative to a standard drug, Amitriptyline in the treatment of peripheral neuropathy.
Methodology: A randomized double blind prospective clinical study was conducted on thirty six patients of peripheral neuropathy divided into two groups of equal number of patients. Group 1 received Ondansetron 8 mg per day while Group 2 received Amitriptyline 25 mg per day. Patients were being evaluated on the basis of improvements (decrease) in LANSS (Leeds Assessment of Neuropathic Symptoms and Signs), VAS (Visual Analogue Scale) and NCV (Nerve Conduction Velocity) for six weeks. Student’s t-test and/or repeated measure ANOVA followed by Bonferoni correlation was used to compare sets of paired observations. The Friedman test followed by multiple comparisons was used to compare the data which was not normally distributed.
Results: LANSS and VAS scores showed significant improvements in the 1st and 2nd visit in both the groups. NCV showed improvement in Ondansetron group with less number of adverse effects compared to that of Amitriptyline. NCV in Amitriptyline group demonstrated significant increase in one of the parameters, F-waves, indicating a worsening in left tibial nerve (p=0.036), whereas no such change was found in the group treated with Ondansetron.
Conclusion: Ondansetron has beneficial role in peripheral neuropathy by improving its sensory component as it significantly decreased LANSS and VAS scores. Our results also demonstrated that Ondansetron was at least as efficacious as Amitriptyline in the treatment of peripheral neuropathy with lesser adverse effects.