Effects of combined swimming exercise and non-steroidal anti-inflammatory drugs on inflammatory nociception in rats

Pain is a growing health problem with an increasing prevalence, and represents a large burden worldwide. Pain control can be achieved through pharmacological and non-pharmacological (such as exercise) interventions. The prolonged use of analgesics, such as non-steroidal anti-inflammatory drugs (NSAIDs), is accompanied by numerous side effects. No previous studies have examined whether exercise may enhance the analgesic effect of NSAIDs. In the present study, the effect of ibuprofen and swimming exercise on nociception threshold were investigated using a rat model of inflammatory pain. A prophylactic swimming protocol and a treatment swimming protocol were used. In the two protocols, nociception was induced by intraplantar injection of Complete Freund's Adjuvant. The authors hypothesized that swimming exercise may enhance ibuprofen-induced antinociception. In the control group, nociception lasted for 17 days, and ibuprofen produced an antinociceptive effect at a dose of 32 mg/kg. However, swimming exercise enhanced ibuprofen-induced antinociception in the two swimming protocols. Notably, ibuprofen produced a significant increase in the nociception threshold at a dose of 10 mg/kg in the prophylactic swimming group. In addition, the duration of inflammation did not exceed 8 days under either swimming protocol. In conclusion, the combination of ibuprofen and swimming exercise was effective in controlling nociception in a rat model of inflammatory pain. Based on these observations, the combined use of exercise and ibuprofen may be a viable intervention for the control of chronic pain, and may decrease the potential for drug-induced side effects.