title: Modification of the analgesic effect and the effect on body temperature of morphine and fentanyl, included in liposomal suspensions.
abstract: The analgesic and thermomodulating effect of the powerful narcotic analgesics morphine and phentanyl, included in liposomal suspensions, was tested in experiments on rats and rabbits. The aim of the experiments was to determine the changes taking place in these effects of the above analgesics, using as their carriers small neutral liposomes formed by phosphatidylcholine (egg lecithin) and cholesterol in molar ratio 7:2. The liposomes were obtained by applying the classical method of A. Bangham (1968), with subsequent ultrasoundtreatment. The changes in the body temperature of the rats and rabbits were traced in dynamics by means of electrothermometry. The analgesic activity was also investigated in dynamics, using two methods: thermal stimulation ("tail flick" test) and mechanical pressure (after Randall-Selitto, 1957). Incorporation of morphin and Fentanyl in liposomal suspensions was found to result in a tendency towards intensification and statistically significant prolongation of their thermomodulating and analgesic effects, compared with these effects of the free preparations. The pharmacological investigations carried out reveal considerable possibilities for a clinically favourable modification of the effects of the narcotic analgesics by means of their incorporation in liposomal carriers.
mesh_terms: D000700:Analgesics; D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D005283:Fentanyl / Q000008:administration & dosage / Q000494:pharmacology*; D006591:Hexobarbital / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D008081:Liposomes; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D010146:Pain / Q000503:physiopathology; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D012684:Sensory Thresholds / Q000187:drug effects; D013535:Suspensions
chemical_list: D000700:Analgesics; D008081:Liposomes; D013535:Suspensions; D009020:Morphine; D006591:Hexobarbital; D005283:Fentanyl