Pentoxifylline (Trental) has no significant effect on laboratory parameters in sickle cell disease

The possible effect of pentoxifylline (Trental) in sickle celle disease was tested in 2 clinical trials: a controlled double-blinded intravenous study involving patients hospitalized with painful crises and an ublinded 5-month oral study in steady state patients. In the intravenous trial 29 painful episodes were treated in 16 patients. Complete blood counts, serum chemistries, red cell density gradients, intracellular pH, p50, whole blood viscosity, plasma viscosity and red cell distribution widths were monitored daily during the hospital admission. We confirmed the decrease of dense red cells during crisis and found, in addition, the related significant decrease in whole blood p50. There were no major differences in any of these parameters when pentoxifylline was compared to placebo for each individual day. When the data was examined over time, minor differences emerged. The red cell distribution width, the number of cells in density fraction SS2 (discocytes) and the plasma viscosity were all slightly higher over time in the pentoxifylline group than in the control group. In the oral group 23 patients were monitored for the same parameters on seven visits during a five month period. Administration of oral pentoxifylline produced no changes from baseline for all parameters examined except for a statistically significant, but minor, increase in plasma viscosity demonstrable for these patients during one visit only. We conclude that pentoxifylline has little effect on laboratory parameters in sickle cell disease.