Effects of psychotropic drugs on thermal responses to radiofrequency radiation.

An increase in body temperature is a primary effect of exposure to high levels of radiofrequency radiation; therefore, pharmacological agents which may modify thermoregulation are of interest. The present study investigated the effects of chlorpromazine, amitriptyline, and haloperidol on thermal responses in anesthetized rats exposed to 2.8 GHz radiofrequency radiation. Exposure was performed at an average power density of 60 mW X cm-2 (average whole body absorption rate, 14 W X kg-1), and was of sufficient duration to increase colonic temperature from 38.5 to 39.5 degrees C. Administration of chlorpromazine (5 mg X kg-1) resulted in a slower rate of colonic temperature rise during radiation exposure and a faster return to baseline temperature when exposure was discontinued. Administration of amitriptyline (10 mg X kg-1), haloperidol (0.1 mg X kg-1), or saline did not significantly affect thermal responses. A more rhythmic pattern of respiration occurred following chlorpromazine administration; the change in pattern was not seen after amitriptyline, haloperidol, or saline administration. The results indicate that acute administration of chlorpromazine can counteract hyperthermia during exposure to radiofrequency radiation, when colonic temperature is not allowed to rise above 39.5 degrees C.