The aim of this study was the evaluation of the influence of a physical factor (electromagnetic field – EMF) on the analgesic efficacy of tramadol in rats with complete Freund’s adjuvant (CFA) induced paw inflammation. Complete Freund’s adjuvant significantly increased sensitivity of inflamed paws to thermal stimulus. Tramadol (TRAM) administered to rats with paw inflammation significantly increased paw withdrawal latency at 30, 60 and 90 minute after drug injection in comparison with non-treated group. Electromagnetic field exposure did not markedly influence nociceptive threshold to thermal stimulus, but significantly decreased paw withdrawal latency in rats treated with tramadol at 30 and 60 minutes from the drug injection.
Conclusion: Electromagnetic field exposure of 1800 MHz frequency and 20 V/m intensity (similar to that of cell phone), did not influence nociceptive threshold to thermal stimuli, however it transiently decreased analgesic efficacy of tramadol in rats with CFA-induced paw inflammation.