Comparative study of efficacy and tolerability of flupirtine versus tramadol in non-steroidal anti-inflammatory drug intolerant mechanical low back pain

Abstract

Mechanical low back pain (MLBP) is a commonly encountered entity in clinical practice. Pain relief and restoration of functional capacity are management goals. To compare the efficacy and tolerability of flupirtine, a selective neuronal potassium channel-opener (SNEPCO), with tramadol, a widely-used opioid analgesic, in MLBP. This randomized, single-blinded, intention to treat (ITT) trial started with 240 non-steroidal anti-inflammatory drug (NSAID) intolerant patients who were prescribed either tablet flupirtine (100 mg twice daily) or capsule tramadol (50 mg twice daily), for 4 weeks. Follow-up was done on days 14, 28 and 4 weeks after treatment completion. Assessment of improvements in Indian Health Assessment Questionnaire Disability Index (Indian HAQ-DI), Visual Analogue Scale (VAS), Numerical Rating Scale (NRS) and measurement of Pain Relief Rate (PRR) were performed. Adverse events were recorded. One hundred and seven patients receiving flupirtine and 103 receiving tramadol were analyzed on an ITT basis. Scores in Indian HAQ-DI, VAS and NRS improved significantly in both groups in the last visit, but more so with flupirtine. PRR was reasonably higher with flupirtine, [59 (55.14%)] patients experiencing significant to complete pain relief at the end of the study, compared to tramadol [41 (39.81%)]. Adverse effects were less with flupirtine [26 (24.30%) versus 41 (39.81%), p < 0.05], minimizing drop-outs. Flupirtine has better sustained efficacy and tolerability than tramadol in MLBP.