In this experiment, effect of diphenhydramine, H_1 receptor antagonist, on the response to pain in rats was studied.
The results were as follows;
1. Diphenhydramine caused significant antinociception as measured by the hot plate method.
2. Diphenhydr...
In this experiment, effect of diphenhydramine, H_1 receptor antagonist, on the response to pain in rats was studied.
The results were as follows;
1. Diphenhydramine caused significant antinociception as measured by the hot plate method.
2. Diphenhydramine potentiated the antinociceptive effect of morphine.
3. Naloxone partially blocks the effect of diphenhydramine in contrast to its effect on morphine.
4. Histamine had no intrinsic antinociceptive activity, nor did it modify the analgesic effect of diphenhydramine or morphine.
From these results, it is suggested that diphenhydramine can stimulated the opiate receptor as well as another mechanism for its antinociceptive action at the different loci.
(Key words : analgesic effect, diphenhydramine)