Dipyridamole treatment in chronic obstructive airways disease: effect on platelet regeneration time.

The platelet regeneration time (PRT) determined in a group of hypoxaemic patients with chronic obstructive airways disease (COAD), before and after treatment with dipyridamole 150 mg tid, was compared with a group of control subjects. The PRT was computed by a modified non-radioisotope technique and was expressed as t1/2 in days. The patient group showed a significantly shortened PRT as compared to controls of the same age and sex (2.10 +/- 0.16 vs 3.65 +/- 0.26 days; p less than 0.001). One month of dipyridamole administration resulted in prolongation of the PRT in COAD patients (2.10 +/- 0.16 days pre-treatment vs 2.75 +/- 0.20 post-treatment; p less than 0.01), without affecting the platelet cyclo-oxygenase system. This study indicates that dipyridamole may be beneficial in pathological conditions, which are characterized by increased platelet turnover, possibly leading to frequent thromboembolic complications.