my personal edition > stroke > news


  E-Mail this DGDispatch to a colleague

DGDispatch

Anti-Stroke Drugs Act on Markers of Vascular Stress: Presented at ESC

By Michael J. Worthington

MANNHEIM-HEIDELBERG, GERMANY -- May 17, 2004 -- Dipyridamole may prevent strokes by reducing certain mediators of vascular stress, including inflammation and endothelial dysfunction, said researchers here May 13^th at the 13^th European Stroke Conference.

Lian Zhao, MD, and colleagues from the Institutes of Neuroscience and Clinical Research, University of Nottingham, United Kingdom, found this result in a study of 3 compounds commonly used to prevent stroke -- aspirin (acetylsalicylic acid, ASA), clopidogrel, and dipyridamole.

"While aspirin and clopidogrel have classical antiplatelet actions, the mechanism of dipyridamole remained unclear [until now]," Dr. Zhao explained during his poster presentation.

The investigators recruited 11 healthy volunteers and 11 patients with prior ischemic stroke or transient ischemic attack (TIA) and treated them in two multiway crossover trials with 2 weeks of aspirin 75 mg once daily, clopidogrel 75 mg once daily, or dipyridamole 200 mg BID. The drugs were given either singly or in combinations of 2 or 3.

After each 2-week treatment period, the researchers took serum and plasma samples and assessed them for markers of vascular stress or inflammation, including C-reactive protein (CRP), cyclic guanylate monophosphate (cGMP), monocyte chemotactic protein (MCP-1), platelet-derived growth factor (PDGF), von Willebrand factor (vWF), plasminogen activator type 1 (PAI-1), and nitric oxide (NO).

Results show that dipyridamole reduced vWF both in healthy volunteers and in stroke patients and CRP in stroke patients only. The drug had no effect on cGMP, MCP-1, and PDGF. Clopidogrel reduced PAI-1 in volunteers but had no effect on other markers. Aspirin had no effect on any of the markers.

According to Dr. Zhao, these findings show that dipyridamole may act primarily on mediators of inflammation (as determined by CRP) and endothelial dysfunction (assessed by vWF), whereas clopidogrel may act primarily through the modulation of fibrinolysis (assessed by PAI-1).

These study findings may provide clues as to how these drugs may be used together or in sequence, Dr. Zhao suggested.


[Presentation title: "Safety and tolerability of simvastatin plus niacin in patients with coronary artery disease and low high-density lipoprotein cholesterol (the HDL Atherosclerosis Treatment Study)."]

E-Mail this DGDispatch to a colleague

To print, use this version