The fundamental first step in any emergency stroke response is a swift and accurate diagnosis, typically using a computed tomography (CT) scan. Since treatment for the two main types of stroke—ischemic (caused by a blood clot) and hemorrhagic (caused by a ruptured blood vessel)—is completely different, this imaging is essential. Administering the wrong medication, such as a clot-busting drug for a hemorrhagic stroke, could be fatal.
Immediate Medication for Ischemic Stroke
Ischemic strokes, which account for about 87% of all strokes, occur when a blood clot blocks blood flow to the brain. The primary goal of immediate treatment is to dissolve the clot and restore blood flow as quickly as possible. This is where "clot-busting" drugs come into play.
The Clot-Buster Drug: Alteplase (tPA)
For many years, recombinant tissue plasminogen activator (rt-PA), known by the generic name alteplase (brand name Activase), has been the standard of care. Alteplase is a thrombolytic agent that works by dissolving the blood clot.
- Administration: Alteplase is given intravenously (IV) through a vein in the arm.
- Time Window: It must be administered within a short, critical time window from the start of symptoms—typically 3 hours, although it can be extended to 4.5 hours in some eligible patients.
- Goal: The faster it is given (often within 90 minutes), the better the patient's chances of recovery and reduced long-term disability.
- Eligibility: Not all patients qualify for alteplase. Contraindications include a prior hemorrhagic stroke, recent surgery, or a severe bleeding disorder.
The Newer Alternative: Tenecteplase (TNK)
Tenecteplase (TNK) is a newer, modified version of alteplase that is gaining traction in some hospitals. Studies suggest it is just as safe and effective as alteplase, with some potential advantages:
- Simpler Administration: Unlike the one-hour infusion required for alteplase, TNK can be given as a single, quick IV bolus injection. This simplified process saves critical time, allowing patients to be moved for other procedures, such as a thrombectomy, more quickly.
- Improved Efficacy: Some research indicates that TNK might be more effective than alteplase at dissolving larger clots.
When Aspirin is the Right Choice
For patients with an ischemic stroke who are not eligible for thrombolytic therapy, an antiplatelet medication like aspirin is typically given within 24 to 48 hours of symptom onset. Aspirin works by preventing platelets from clumping together to form new clots or enlarge existing ones. It is not a clot-buster but is an important part of treatment when thrombolytics are not an option or after thrombolytics have been administered and other risks have subsided.
Immediate Medication for Hemorrhagic Stroke
A hemorrhagic stroke occurs when a blood vessel in the brain ruptures or leaks. Because this involves bleeding, administering blood-thinning medication is dangerous and therefore strictly avoided. Immediate treatment focuses on controlling the bleeding, managing blood pressure, and preventing complications.
- Controlling Anticoagulation: If the patient was on anticoagulant medication (blood thinners) before the stroke, such as warfarin or heparin, doctors will immediately take steps to reverse its effects. This often involves administering agents like vitamin K or other specific reversal agents.
- Blood Pressure Management: High blood pressure is a common cause of hemorrhagic stroke and needs to be carefully controlled to prevent further bleeding. Intravenous medication such as labetalol or nicardipine may be used to lower and maintain blood pressure within specific target ranges.
- Nimodipine for Subarachnoid Hemorrhage (SAH): For a specific type of hemorrhagic stroke known as subarachnoid hemorrhage (bleeding in the space surrounding the brain), the medication nimodipine is administered. This calcium channel blocker helps prevent delayed cerebral ischemia by mitigating cerebral vasospasm, a complication where blood vessels in the brain narrow and restrict blood flow.
The Role of Blood Pressure Management
Regardless of the stroke type, managing blood pressure is a crucial part of immediate stroke care, with different goals for each scenario.
- For Ischemic Stroke: The approach is cautious. For those not receiving thrombolytics, some degree of permissive hypertension (allowing blood pressure to remain elevated) is generally accepted, as high pressure might help push blood through blocked vessels to the brain. However, if blood pressure is dangerously high (>220/120 mm Hg), it will be lowered gradually. For patients receiving alteplase, blood pressure must be kept below 185/110 mm Hg before treatment and below 180/105 mm Hg for the 24 hours following.
- For Hemorrhagic Stroke: The strategy is more aggressive. The goal is to lower blood pressure quickly but safely to prevent further bleeding and hematoma expansion.
Mechanical Intervention: Endovascular Thrombectomy
For patients with a large vessel occlusion (LVO) in an ischemic stroke, a procedure called endovascular thrombectomy may be used in addition to or instead of thrombolytic drugs. This procedure involves inserting a catheter into an artery and guiding a stent retriever to physically remove the clot. This has been shown to be more effective than tPA alone for severe strokes caused by large clots. The time window for thrombectomy can be longer than for alteplase, sometimes up to 24 hours in select patients.
Comparison of Immediate Stroke Treatment Strategies
| Feature | Ischemic Stroke | Hemorrhagic Stroke |
|---|---|---|
| Cause | Blood clot blocks artery to the brain. | Ruptured blood vessel in or around the brain. |
| Initial Diagnostic Scan | Non-contrast CT or MRI to rule out bleeding. | Non-contrast CT or MRI to confirm bleeding. |
| Primary Medication | Thrombolytics: alteplase (tPA) or tenecteplase (TNK) within a strict time window. Antiplatelets: Aspirin if not a thrombolytic candidate. | None: Clot-busters are contraindicated. Blood Pressure Drugs: IV medication like labetalol or nicardipine for aggressive control. Reversal Agents: For patients on anticoagulants. Nimodipine: For subarachnoid hemorrhage to prevent vasospasm. |
| Blood Pressure Goal | Carefully controlled, with a specific, permissive range depending on eligibility for alteplase. | Lowered quickly and controlled to reduce bleeding. |
| Additional Treatment | Endovascular Thrombectomy: For large vessel occlusions, often combined with tPA. | Surgery: To clip an aneurysm or remove a large blood clot. |
Conclusion
Understanding what medicine is given for a stroke immediately begins with the critical realization that not all strokes are the same. The lightning-fast assessment in the emergency room, aided by imaging, determines the correct and life-saving course of action. For an ischemic stroke, time is brain, and clot-busting agents like alteplase or tenecteplase are the first line of defense if administered within the tight time window. For a hemorrhagic stroke, the focus shifts to controlling bleeding and managing blood pressure. In all cases, the key is rapid response, highlighting why calling 9-1-1 at the first sign of stroke symptoms is the most important step one can take.
