Medications

Intra-Arterial Thrombolytics. Researchers are investigating thrombolytics injected directly into an artery in the brain. Early studies suggest this approach may allow effective treatment up to 6 hours after a stroke and improve recovery in more patients. The risk for bleeding and hemorrhagic stroke is significantly increased, however.

Fibrin-Depleting Drugs. These drugs deplete the amount of fibrinogen in blood, which in turn reduces the "stickiness" in blood. Such drugs include ancrod and batroxobin (Defibrase), both derived from the venom of poisonous snakes. Some experts believe these drugs might be a possible alternative to thrombolytics. Studies suggest they may modestly reduce the risks for death and disability if given early on. As with all anti-clotting drugs, there is a higher risk for hemorrhage, but it appears to be slight.

Anticlotting Medications for Preventing a Recurring Stroke

Medications that prevent blood from clotting are used to prevent a recurring or second stroke. Anticlotting drugs include antiplatelets and anticoagulants.

Antiplatelet Drugs.Blood platelets are involved in blood clotting. Antiplatelets prevent clotting by blocking the accumulation of platelets. An antiplatelet drug -- most often aspirin -- is given within 48 hours of an ischemic stroke and continued in low doses as maintenance therapy. Studies suggest that antiplatelet therapy can reduce the risk for a second stroke by 25%.

• Aspirin. Aspirin is recommended within 48 hours of a first ischemic stroke in doses of between 50 and 325 mg. Daily low-dose aspirin may also help prevent a second ischemic stroke. Experts also recommend aspirin combined with the antiplatelet drug dipyridamole (Aggrenox). Patients should not be given an aspirin until a diagnosis of ischemic or hemorrhagic stroke has been determined. Aspirin increases the risk for bleeding in patients with hemorrhagic stroke and can be dangerous.
• Thienopyridines. Clopidogrel (Plavix) and ticlopidine (Ticlid) are antiplatelet drugs known as thienopyridines. (Clopidogrel is preferred over ticlopidine because of its better safety record.) Evidence suggests that clopidogrel plus aspirin is better than aspirin alone in reducing blood clots in patients who have carotid artery blockage (carotid stenosis). Other studies indicate that clopidogrel alone may be sufficient for patients who have had a recent ischemic stroke or TIA. A study of over 7,000 of these patients found that adding aspirin to clopidogrel therapy provided no additional benefit and increased the risk of bleeding; therefore, aspirin plus clopidogrel is not usually recommended for most patients who have had an ischemic stroke or TIA. Clopidogrel alone may also be better than aspirin alone in preventing a third stroke or heart attack in high-risk patients.
• Glycoprotein IIB/IIIa Inhibitors. Glycoprotein IIb/IIIa (GPIIb/IIIa) inhibitors are sometimes administered intravenously in the hospital and include abciximab (ReoPro, Centocor), eptifibatide (Integrilin), tirofiban (Aggrastat), lotrafiban, and lamifiban. They are being investigated alone or as additions to thrombolytic (clot-busting) drugs.