Diclofenac sodium (Voltaren) reduced exercise-induced injury in human skeletal muscle

Purpose: To examine the effects of prolonged systemic administration of dic lofenac sodium (Voltaren), a nonsteroidal anti-inflammatory drug, on object ive indices of exercise-induced muscle damage in humans. Methods: Fifty-fou r volunteers (mean age, 26.4 yr; range, 18-35) participated in this randomi zed double-blind, placebo-controlled trial. To achieve steady-state tissue levels, either placebo or diclofenac was orally administered two limes a da y for 27 consecutive days. A strenuous 20-min stepping exercise program, ab out which the subjects were unfamiliar, was conducted on day 15. Creatine k inase (CK) activities were measured immediately before the exercise session and on days 16, 18, and 27. Vastus lateralis muscle samples were obtained immediately before exercise and on day 27 for subsequent histological chara cterization of muscle inflammation. Results: The preexercise muscle samples revealed no difference in muscle damage between the two groups. However, t he postexercise muscle samples showed that the diclofenac-treated group dem onstrated less muscle tissue damage than placebo-treated subjects (P = 0.00 2). The administration of diclofenac also resulted in a significant lowerin g of post-/pre-exercise CK ratios on days 18 (P = 0.03) and 27 (P = 0.02) c ompared with the placebo group, an indirect finding that supports the possi bility of diclofenac reducing exercise-induced muscle damage. Conclusion: T hese findings demonstrate preadministration of diclofenac (in accordance wi th tissue half-life phamacokinetics) significantly reduces quantitative ind ices of exercise-induced skeletal muscle damage in human muscle.