Does a rhythmicity of serum concentrations and urinary excretion of dipyridamole exist during long-term treatment?

No daily rhythmicity of changes in dipyridamole (Curantyl-Germed) concentration in the blood serum of chronically treated patients receiving orally 75 mg of dipyridamole every 8 hr was found. The urinary excretion of dipyridamole was 1.37 mg/day (0.6% of the daily dose) and was significantly lower between 18.00--2.00 hr in comparison with excretion between 2.00--0.00 and 10.00-18.00.