Enhancement of morphine-induced hyperactivity by antihistaminic drugs in mice.
Three histamine H1-receptor antagonists, chlorpheniramine, diphenhydramine and tripelennamine, were tested alone or in combination with morphine on locomotor activity in C57BL/6 mice. All three antihistaminics, at some dosage levels, slightly increased activity when given alone, but strongly enhanced morphine-induced hyperactivity. The results demonstrate that locomotor activity represents a useful test to evidence stimulatory effects of antihistaminic-opiate combinations.
D000818:Animals; D002744:Chlorpheniramine / Q000008:administration & dosage; D004155:Diphenhydramine / Q000008:administration & dosage; D006634:Histamine H1 Antagonists / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009020:Morphine / Q000008:administration & dosage*; D009043:Motor Activity / Q000187:drug effects*; D014309:Tripelennamine / Q000008:administration & dosage
D006634:Histamine H1 Antagonists; D014309:Tripelennamine; D002744:Chlorpheniramine; D009020:Morphine; D004155:Diphenhydramine