Effect of olprinone, phosphodiesterase III inhibitor, on cerebral blood flow assessed with technetium-99m-ECD SPECT

Few clinical reports exist regarding the effects of phosphodiesterase III i nhibitors on cerebral arteries. Therefore we used a [Tc-99m]-ECD brain SPEC T and an ultrasound method to quantitatively evaluate cerebral and systemic flow dynamics after the administration of olprinone, a phosphodiesterase I II inhibitor. In 15 patients (65 +/- 8 years, M/F = 13/2) with no abnormali ties on a brain computed tomography (CT), cerebral blood flow and cardiac o utput were measured using [Tc-99m]-ECD brain SPECT and Doppler echocardiogr aphy, respectively. Measurements were repeated at baseline and after the ad ministration of olprinone. Significant increases in cerebral blood now (p = 0.0007) and cardiac output (p = 0.001) were observed, and systolic blood p ressure (p = 0.02) and systemic vascular resistance (p = 0.002) significant ly decreased. No significant correlation between the increase in cerebral b lood flow and the increase in cardiac output was observed. The data indicat e that olprinone has a direct vasodilator effect on the cerebral artery, wh ich was little related to the increase in cardiac output in patients who ha d not experienced stroke.