Pharmacokinetics of oral dipyridamole (Persantine) and its effect on platelet adenosine uptake in man.

Two preparations of dipyridamole have been studied by oral administration to 11 normal volunteers. The plasma levels of dipyridamole and its glucuronide were determined simultaneously by high performance liquid chromatography. The instant form (I.F., 100 mg) was administered four times daily and the slow release preparation (SRP, 200 mg) twice daily, for 3 days. Multiple blood samples were collected on Days 1-4 to provide plasma for assay, and simultaneously, platelet rich plasma was prepared for ex vivo study of the effect of dipyridamole on platelet uptake of adenosine. The pharmacokinetics of absorption and distribution of dipyridamole were described using a two compartment model with lag time and prolonged absorption. Strong inhibition of the platelet adenosine uptake was observed at therapeutic plasma levels. The inhibition of platelet adenosine uptake may be related to some of the pharmacological properties of dipyridamole.