cinnarizine and Cardiovascular-Diseases

In order to understand blood circulation, knowledge of the rheological properties of blood is required. However, the characteristic parameters which must be considered differ according to the circulatory region investigated. A distinction must therefore be made between the macrorheological parameters (viscosity, viscoelasticity) and the microrheological parameters (aggregation, cell deformability). As far as the microrheological parameters are concerned, red blood cell deformability is quite definitely the most important parameter in any physiopathological study of capillary circulation and the resulting exchanges. The main intrinsic parameters of red blood cell deformability are: inner viscosity of the cell, surface/volume ratio and membrane properties related to the lipid bilayer or to the cytoskeleton. Abnormal erythrocyte microrheology may result form alterations any one of these three parameters and would affect the ability of the cell to transit in the capillaries. Disturbances of red blood cell deformability are encountered in many clinical cases, mainly during anomalies relating to hemoglobin structure or its oxygen affinity, in constitutional deficiency of the membrane and during degenerative cardiovascular diseases or diseases which are considered to be atherosclerosis risk factors.

Topics: Animals; Arteriosclerosis; Blood Viscosity; Calcium; Cardiovascular Diseases; Cinnarizine; Elasticity; Erythrocyte Indices; Erythrocyte Membrane; Erythrocytes; Hematologic Diseases; Humans; Membrane Fluidity; Microcirculation; Models, Biological; Pentoxifylline; Rheology; Risk

The natural course of calcium-entry blocker-induced parkinsonism was evaluated in 13 elderly patients previously exposed to cinnarizine or flunarizine or both for a median period of 7 months. Clinical assessments were carried out before drug discontinuation and twice thereafter over a period lasting < or = 7 years. None of the patients showed a full recovery of extrapyramidal signs, indicating that the long-term prognosis of the parkinsonism is less benign than previously reported. Two main patterns of clinical outcome were recognized (i.e., "remittent" and "persistent and not progressive" parkinsonism), whereas the development of a progressive disorder was observed only in one patient. No significant correlation was found between the patterns of outcome and some clinical variables, such as total duration of exposure to cinnarizine and flunarizine, cumulative drug dosages, and age at onset of parkinsonism. There was no significant difference in terms of family history of essential tremor or parkinsonism or both among patients with the two main patterns of clinical course.

Topics: Aged; Calcium Channel Blockers; Cardiovascular Diseases; Cinnarizine; Dose-Response Relationship, Drug; Female; Flunarizine; Follow-Up Studies; Humans; Male; Middle Aged; Neurologic Examination; Parkinson Disease, Secondary; Treatment Outcome