What is the appropriate pharmacologic management for an acute cerebral infarction?

Acute Cerebral Infarction Management

For acute cerebral infarction, immediately administer IV alteplase (0.9 mg/kg, maximum 90 mg) if the patient presents within 4.5 hours of symptom onset and meets eligibility criteria, with treatment initiated as rapidly as possible since every minute of delay worsens outcomes.

Time-Critical Thrombolysis Protocol

The cornerstone of acute ischemic stroke treatment is IV alteplase, with efficacy directly tied to speed of administration 1:

Within 3 Hours of Symptom Onset

• Dose: 0.9 mg/kg (maximum 90 mg) over 60 minutes, with 10% given as initial bolus over 1 minute
• Eligibility: All patients ≥18 years, including those >80 years old
• Severity: Even severe strokes benefit despite increased hemorrhagic transformation risk
• Class I, Level of Evidence A recommendation 1

3-4.5 Hour Window

• Same dosing as above
• Additional restrictions for this extended window:
  • Age ≤80 years
  • No history of BOTH diabetes AND prior stroke
  • NIHSS score ≤25
  • Not taking oral anticoagulants
  • No imaging evidence of ischemic injury >1/3 MCA territory
• Class I, Level of Evidence B-R 1

Critical Pre-Treatment Requirements

Before administering alteplase, ensure 1:

Blood Pressure Management:

• Must be safely lowered to <185/110 mmHg before thrombolysis
• Maintain <180/105 mmHg for at least 24 hours post-treatment

Blood Glucose:

• Alteplase recommended for glucose >50 mg/dL
• Treat hyperglycemia >155 mg/dL 2

Imaging:

• Non-contrast CT to exclude hemorrhage (absolute contraindication)
• Mild-to-moderate early ischemic changes acceptable
• Extensive frank hypodensity is a contraindication

Prior Antiplatelet Use:

• Monotherapy (e.g., aspirin alone): Safe to proceed
• Dual antiplatelet therapy (e.g., aspirin + clopidogrel): Safe to proceed despite slightly increased sICH risk 1

Absolute Contraindications

Do NOT give alteplase if 1:

• Intracranial hemorrhage on CT
• Ischemic stroke within past 3 months
• Severe head trauma within 3 months
• Intracranial/spinal surgery within 3 months
• Time last known well >4.5 hours

Post-Thrombolysis Management

Antiplatelet Therapy Timing:

• Avoid antiplatelets for 24 hours after alteplase administration 1
• Exception: May consider earlier if compelling indication where withholding poses substantial risk (Class IIb)

If Alteplase NOT Given:

• Start aspirin 160-325 mg within 48 hours of symptom onset 3, 4
• This prevents 7 ischemic recurrences per 1000 patients treated 4

Endovascular Therapy Consideration

For patients with large vessel occlusion:

• Mechanical thrombectomy improves disability-free survival 4
• Can be performed up to 6-24 hours in selected patients using multimodal imaging 4, 5
• Does not preclude IV alteplase—combination therapy is standard for eligible patients

Supportive Care Essentials

All patients require 2:

• Stroke unit admission (improves outcomes independent of other treatments)
• Temperature control: Treat fever >37.5°C with antipyretics
• DVT prophylaxis: Subcutaneous LMWH or pneumatic compression for immobile patients 3
• Early rehabilitation initiation

Common Pitfalls to Avoid

1. Delaying treatment for "minor" strokes: Even mild deficits benefit from thrombolysis within the time window
2. Withholding due to age >80: Age alone is NOT a contraindication in the 0-3 hour window 1
3. Starting aspirin too early: Wait 24 hours post-alteplase to minimize hemorrhage risk
4. Missing the blood pressure target: Failure to achieve <185/110 mmHg pre-treatment is a common reason for exclusion

The number needed to treat is remarkably favorable: 1 additional disability-free survivor for every 3 patients treated within 90 minutes, 7 within 3 hours, and 14 within 4.5 hours 4. This underscores the critical importance of rapid evaluation and treatment initiation—"time is brain."