Dipyridamole is a medicine that inhibits thrombus formation when given chronically and causes vasodilation when given at high doses over a short time. Dipyridamole inhibits the phosphodiesterase enzymes that normally break down cAMP (increasing cellular cAMP levels and blocking the platelet response to ADP) and/or cGMP. It inhibits the cellular reuptake of adenosine into platelets, red blood cells and endothelial cells leading to increased extracellular concentrations of adenosine. Dipyridamole overdose can be treated with aminophylline[10] which reverses its hemodynamic effects (vasodilation). Symptomatic treatment is recommended, possibly including a vasopressor drug. Gastric lavage should be considered. Administration of xanthine derivatives (e.g., aminophylline) may reverse the hemodynamic effects of dipyridamole overdose. Since dipyridamole is highly protein bound, dialysis is not likely to be of benefit.
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