Background: Many stroke survivors have severe dysphagia and are unable to take antithrombotic medications orally.
Objective: To evaluate whether dipyridamole concentrations achieved in the plasma of patients taking an extended-release formulation of the medication through a gastrostomy tube (G-tube) are therapeutic and similar to those achieved in the plasma of patients who receive the drug orally.
Methods: This was an open-label, case-control, two-centre study conducted in two academic centres in a metropolitan area. Patients included were those admitted following an acute cerebral infarction, with an indication for antiplatelet therapy for secondary prevention. Twelve patients with severe dysphagia requiring G-tube placement were cases, and 12 patients who were able to swallow safely served as controls. The components of Aggrenox (extended-release dipyridamole/aspirin [acetylsalicylic acid]), suspended in water, were administered twice daily for 5 days through the G-tube. The 12 control patients without dysphagia took the medication orally. Dipyridamole plasma concentrations were compared between the groups at three different timepoints on the fifth day: 2, 6 and 12 hours after administration. The main outcome measure was dipyridamole plasma concentrations on day 5 at all three timepoints.
Results: No significant difference in dipyridamole plasma concentrations between the groups was found at 2 hours (p = 0.18), 6 hours (p = 0.92) or 12 hours (p = 0.69).
Conclusion: Dipyridamole plasma concentrations obtained following administration of extended-release dipyridamole through a G-tube in dysphagic patients achieved similar therapeutic levels to those obtained in patients taking the medication orally.