A DOUBLE-BLIND CROSS-OVER STUDY COMPARING THE ANALGESIC EFFICACY OF TRAMADOL WITH PENTAZOCINE IN PATIENTS WITH OSTEOARTHRITIS

Tramadol (50 mg qds) and pentazocine (50 mg tds) were compared in a do uble-blind cross-over study of 40 patients with painful osteoarthritis of the hip and/or knee confirmed by radiological evidence. The primar y efficacy variable was the severity of pain as recorded on the diary cards completed daily by each patient Duration of morning stiffness an d its severity and the number of paracetamol tablets consumed were als o recorded. Tramadol was more effective than pentazocine when assessed by pain scores recorded by patients on a daily diary card (cohort 1, p = 0.089; cohort 2, p = 0.030). Tramadol was also more effective than pentazocine when compared in terms of morning stiffness (p = 0.034) a nd paracetamol consumption (p = 0.073). In terms of overall assessment of efficacy, patients rated tramadol more highly than pentazocine (p = 0.003). Spontaneous symptoms were reported by 18/34 (53%) patients w ho took tramadol and 28/36 (78%) patients who took pentazocine. Ten pa tients withdrew during the first treatment period (four on tramadol, s ix on pentazocine), and 11 withdrew during the second treatment period (five on tramadol, six on pentazocine). The majority of withdrawals w ere due to spontaneous symptoms. On the grounds of both efficacy and f ewer spontaneous symptoms, tramadol appeared preferable to pentazocine in the treatment of osteoarthritis and thus would appear a useful alt ernative to those opioids or opioid-containing drugs currently availab le.