Effect of a single pentoxifylline administration on platelet sensitivity, plasma factor activity, plasma-6-oxo-PGF1 alpha and thromboxane B2 in healthy volunteers.

In eight male healthy volunteers aged 25-38 years 300 mg pentoxifylline (Trental, Hoechst AG, Frankfurt/M., Germany) were administered intravenously by a short term infusion for 10 minutes. Blood was withdrawn before as well as 30, 60, 90 and 120 minutes after the infusion. Throughout the entire investigation the volunteers were kept in an upright sitting position in a comfortable chair. Plasma levels of 6-oxo-PGF1 alpha and thromboxane B2 (TXB2), PGI2 release stimulating plasma factor (PF) activity and the platelet sensitivity to PGE and PGI respectively were evaluated at each interval. Plasma levels of 6-oxo-PGF1 alpha exhibited a significant (p less than 0.001) increase in mean values after pentoxifylline administration, reaching the maximum at 60 minutes after infusion. Only a trend (p less than 0.05) was detectable for a decrease in plasma TXB2 values. The PF activity did not change throughout the follow-up period. The platelet sensitivity to PGI2, however, exhibited a significant (p less than 0.01) increase as did sensitivity to PGE1 (p less than 0.005). These results are in accordance with earlier data showing that pentoxifylline is able to increase PGI formation by various tissues. The findings suggest, that the beneficial effects reported for this compound in clinical use might in part be due to its positive effects in local hemostatic regulation.