Effects of CD-832, a new calcium antagonist, on intracranial pressure in anesthetized dogs

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), ICP, VBF and CCBF were measured before and during the continous intravenous infusion of CD-832 (0.3, 1 and 3 μg/kg/min), nifedipine (0.1, 0.3 and 1 μg/kg/min) or diltiazem (1, 3 and 10 μg/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.