Effect of Gabapentin and Pregabalin in Rat Model of Taxol Induced Neuropathic Pain

Background: Chemotherapy induced neuropathy pain remains as a major dose limiting side effect of many commonly used chemotherapeutic drugs. Presently newer antiepileptic agents have been developed with improved safety and tolerability profiles in alleviating neuropathic pain. Objectives: To evaluate the effect of Gabapentin and Pregabalin in Paclitaxel (Taxol) induced neuropathic pain and to compare the effect of these drugs in animal models. Materials and Methods: Rats were randomly divided into four groups of six animals each. Group 1-vehicle, Group 2 - Paclitaxel (2mg/ kg), Group 3 - Gabapentin (60mg/kg) with Paclitaxel, Group 4 - Pregabalin (30mg/kg) with Paclitaxel. Pain was induced by intraperitoneal injection of Paclitaxel on four alternate days. After taking the baseline values, the drugs treated groups (group 3 and 4) were administered with respective drugs once a day orally for eight consecutive days along with paclitaxel. All the animals were tested for thermal hyperalgesia and cold allodynia on day 0, 7, 14, 21 and 28 with Radiant heat method and Tail immersion test, Acetone drop method respectively. Results: In Radiant heat method, gabapentin and pregabalin treated animals found to have significant increase in the tail latency period compared to control and paclitaxel treated groups in all periods of observation. Acetone drop test and tail immersion test also showed significant response similar to Radiant heat method. Pregabalin showed highly significant effect when compared to gabapentin group. Conclusion: Both gabapentin and pregabalin produced significant anti-hyperalgesic and anti-allodynic effects in experimental animal models. Pregabalin treated group showed highly significant effect compared to gabapentin treated animals.