The interaction of cimetidine with various antihypertensive agents in the spontaneously hypertensive rat.
The H2-receptor antagonist cimetidine (250 micrograms) administered intracerebroventricularly (i.c.v.) 15 and 30 min before clonidine (25 micrograms kg-1 i.v.), significantly antagonized clonidine-induced hypotension in anaesthetized spontaneously hypertensive rats. The hypertensive response of cimetidine was correlated with the inhibition of clonidine-induced hypotension. In addition, cimetidine (250 micrograms i.c.v.) counteracted the hypotensive effects of pentolinium (5.0 mg kg-1 i.v.), guanethidine (5.0 mg kg-1 i.v.) and minoxidil (1.0 mg kg-1 i.v.) These data do not support previous suggestions that the hypotensive action of clonidine is caused by stimulation of the H2-receptor, but suggest that central administration of cimetidine causes peripheral vasoconstriction and this may offer resistance to the hypotensive action of different antihypertensive agents.
Dadkar
N K
NK
Aroskar
V A
VA
Gupte
R D
RD
Dohadwalla
A N
AN
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002927:Cimetidine / Q000494:pharmacology*; D003000:Clonidine / Q000037:antagonists & inhibitors; D006145:Guanethidine / Q000037:antagonists & inhibitors; D007276:Injections, Intraventricular; D008297:Male; D008914:Minoxidil / Q000037:antagonists & inhibitors; D010425:Pentolinium Tartrate / Q000037:antagonists & inhibitors; D051381:Rats; D011918:Rats, Inbred SHR; D013997:Time Factors
D000959:Antihypertensive Agents; D008914:Minoxidil; D002927:Cimetidine; D010425:Pentolinium Tartrate; D003000:Clonidine; D006145:Guanethidine