Effects of a new
calcium antagonist,
CD-832, on intracranial pressure (ICP), vertebral blood flow (VBF) and common carotid blood flow (CCBF) were investigated in dogs and the results were compared with findings for
nifedipine and diltiaem. Dogs were anesthetized with
sodium pentobarbital and a 20-gauge needle was inserted into the cisterna magna for ICP determination. Mean arterial blood pressure (MBP), heart rate (HR), CP, VBF and CCBF were measured before and during the continuous
intravenous infusion of
CD-832 (0.3, 1 and 3 microg/kg/min),
nifedipine (0.1, 0.3 and 1 microg/kg/min) or
diltiazem (1, 3 and 10 microg/kg/min). Although the three drugs caused a comparable
hypotension, differences were evident in effects of these agents on ICP, VBF and CCBF.
Nifedipine and
diltiazem but not
CD-832 significantly increased ICP, VBF and CCBF. These results suggest that
CD-832 is a unique
calcium antagonist which does not increase ICP during
hypotension. Because the most evident side effects of
calcium antagonists are caused by vasodilation and include
headache and
flushing,
CD-832 may possibly be useful to treat subjects with
hypertension or
angina pectoris.