Cardiovascular effects of
cinepazide were compared with those of
cinnarizine and
papaverine.
Cinepazide (3-30 mg/kg, i.v.) produced a dose-related and transient increase in vertebral, carotid, renal and femoral arterial flow as well as cardiac output and a decrease in total peripheral resistance in anesthetized dogs. The magnitude and duration of mesenteric vasodilatation induced by
cinepazide was much greater as compared to other vascular effects, and these effects were associated with a prolonged
hypotension. The
drug exerted positive inotropic and chronotropic actions, the latter being followed by
bradycardia with the highest dose.
Cinnarizine (0.3-3 mg/kg, i.v.) produced a greater increase in vertebral blood flow with
bradycardia and
papaverine (0.1-1 mg/kg, i.v.) produced a remarkable carotid vasodilatation with cardiac stimulation. Both reference drugs decreased renal blood flow.
Cinepazide (30 mg/kg, i.v.) potentiated the vertebral
vasodilator response of dogs to intravertebral
adenosine and
cyclic AMP, while
cinnarizine (3 mg/kg i.v.) reduced their
vasodilator effects. Intravertebral cinepazide(1-10 mg), like
cinnarizine (0.1-1 mg) and
papaverine (0.1-1 mg), increased vertebral blood flow in a dose-related manner and the effect was partially inhibited by intravenous pretreatment with
aminophylline but not by pretreatment with autonomic antagonists. These antagonists did not modify the
cinnarizine effect.
Cinepazide resembled
cinnarizine and
papaverine in that the
drug antagonized rabbit aortic contraction induced by KCl,
norepinephrine or CaCl2.