Rheological effects of pharmacological treatment of inner ear disorders.

Improvement of the rheological quality of circulating blood is an important factor in pharmacological treatment of inner disorders. Diminution of blood viscosity by increased fluidity of red blood cells and hemodilution was studied in two patient groups, one treated by pentoxifylline per os (Trental 400, Höchst) and dextran infusions, the other one by dextran infusions only. The dextran effect is a short-term hemodilution, i.e. decreased viscosity is identical to hematocrit reduction. Long term, however, there is a significant increased viscosity in the dextran group. A significant constant effect on blood viscosity is warranted by pentoxifylline. Oral administration of this drug prevents the long-term blood thickening effect of dextran and leads to a permanent improvement of microcirculation.