Caffeine interferes with morphine-induced hyperactivity but not analgesia
Oliverio, A.; Castellano, C.; Pavone, F.; Vetulani, J.
Polish Journal of Pharmacology and Pharmacy 35(6): 445-449
1983
ISSN/ISBN: 0301-0244 PMID: 6677894 Document Number: 200731
In C57BL/6 mice caffeine antagonized morphine-induced hyperactivity. This effect was most evident when caffeine was used in doses that slightly increased locomotor activity. Given at the same dose caffeine did not affect morphine-induced analgesia. Two possibilities of explanation of this effect are discussed: action of caffeine on dopaminergic mechanisms responsible for morphine-induced running fit through its effect on cyclic AMP level, and a direct action of caffeine on delta opiate receptors involved in the stimulatory effect of morphine.