Randomized Double-Blind Study of the Efficacy, Safety and Tolerability of Tenoxicam Versus Diclofenac Sodium in the Management of Arthritis and Painful Musculoskeletal Conditions in Adult Nigerian Volunteers

Abstract

The efficacy, safety and tolerability of the thieno-thiazine (oxicam) derivative – tenoxicam versus Phenyl acetic acid derivative –diclofenac in the management of arthritis and painful musculoskeletal conditions have been evaluated in an 8-week randomized double-blind comparative study. The 32 enrolled patients began the study with a 7 days washout period during which they received placebo (phase 1). Patients were then randomized to receive tenoxicam 20mg/day or diclofenac. 100mg/day for 8 weeks (Phase II). A total of ten visits were performed blood on weeks 0, 0.29, 1, 2, 3, 4, 5, 6, 7, 8. Pre- and post-treatment blood samples were collected from each patient for the evaluation of blood chemistry, haemogram profile and other laboratory parameters. Patients were also asked at each clinic visit if they have experienced any new symptoms or changes since the previous visit. Thirty-two (32) patients (43.8% men) were assigned to receive tenoxicam (n=18) or diclofenac (n=14). Seventeen (17) patients treated with tenoxicam and 13 patients treated with diclofenac were considered evaluable for efficacy. At the end of active treatment phase, 88% (15/17) of the patients treated with tenoxicam were considered therapeutic successes, compared with 69% (9/13) in diclofenac group. However, the difference in therapeutic successes between the two groups was not statistically significant (p<0.05, n=30). Laboratory findings showed that tenoxicam had no adverse effect on haematological, homeostasis and biochemical values with a statistically significant reduction in Erthrocytes Sedimentation Rate (ESR) (29.87 to 9.5mm/h). There was significant functional improvement and excellent control of disease activity (p<0.001, n=17) compared to diclofenac whose difference (28.77 to 21.33mm/h) is not statistically significant (p<0.05, n=13). Safety and tolerability data showed that both treatments were well-tolerated. The percentage of adverse events and discontinuation was 17.65 and 5.88% with tenoxicam versus 23.08 and 7.69% with diclofenac respectively. These results showed that there was a statistically significant higher mean symptoms improvement in 20mg daily tenoxicam than the 100mg daily diclofenac. Tenoxicam also exhibited faster onset and longer duration of therapeutic activity. Both drugs were well-tolerated.

Keywords: Randomized Double-Blind Study, Efficacy, Safety, Tolerability Tenoxicam, Diclofenac Sodium, Arthritis.

NQJHM Vol. 15 (4) 2005: pp. 186-194