A 58-year-old man with diabetes and hypertension presents to the emergency department with acute anterior wall ST-elevation myocardial infarction (STEMI) of 2 hours duration. He is hemodynamically stable with no contraindications to fibrinolysis. The hospital does not have PCI capability and transfer to a PCI-capable centre will take 90 minutes. What is the drug of choice for immediate reperfusion therapy?

Question

Accepted Answer

A. Tenecteplase. ## First-Line Fibrinolytic in STEMI

**Key Point:** Tenecteplase is the preferred fibrinolytic agent for STEMI when primary PCI is not available within 120 minutes of symptom onset.

### Why Tenecteplase?

1. **Superior fibrin specificity** — Tenecteplase has greater fibrin selectivity compared to other thrombolytics, resulting in less systemic fibrinogenolysis and reduced bleeding risk.
2. **Single bolus administration** — Can be given as a weight-based IV bolus over 5–10 seconds, improving ease and speed of administration in the acute setting.
3. **Faster reperfusion** — Achieves TIMI 3 flow more rapidly than alteplase or streptokinase.
4. **Lower intracranial hemorrhage (ICH) risk** — Meta-analyses show tenecteplase has a lower ICH rate compared to alteplase, particularly in elderly patients.

### Comparative Profile

| Agent | Fibrin Specificity | Route | Dosing | ICH Risk | NSTEMI Use |
| --- | --- | --- | --- | --- | --- |
| **Tenecteplase** | High | IV bolus | Weight-based, single dose | Lowest | Yes |
| Alteplase | Intermediate | IV infusion | Weight-based, 90 min protocol | Moderate | Yes |
| Streptokinase | Low | IV infusion | Fixed dose, 60 min | Moderate–high | No |
| Urokinase | Low | IV infusion | Weight-based | Moderate–high | Rarely used |

**High-Yield:** Tenecteplase is now preferred over alteplase in most international guidelines (ESC, ACC/AHA) for STEMI fibrinolysis due to superior safety and efficacy profile.

### Clinical Context

**Clinical Pearl:** In this scenario, the patient is within the 2-hour window and PCI is delayed >90 minutes. Fibrinolysis is indicated, and tenecteplase is the agent of choice. Dosing is 30–50 mg IV bolus based on weight (<60 kg: 30 mg; 60–70 kg: 35 mg; 70–80 kg: 40 mg; 80–90 kg: 45 mg; >90 kg: 50 mg).

**Warning:** Do not delay fibrinolysis waiting for transfer if PCI-capable centre is >120 minutes away. "Time is muscle" — every 30-minute delay in reperfusion increases 1-year mortality by ~7.5%.

[cite:Harrison 21e Ch 297]

Answer

B. Streptokinase

Answer

C. Alteplase (tissue plasminogen activator)

Answer

D. Urokinase

Explanation

First-Line Fibrinolytic in STEMI

Why Tenecteplase?

Comparative Profile

Clinical Context

Practice similar questions

Join our NEET PG community

Agent	Fibrin Specificity	Route	Dosing	ICH Risk	NSTEMI Use
Tenecteplase	High	IV bolus	Weight-based, single dose	Lowest	Yes
Alteplase	Intermediate	IV infusion	Weight-based, 90 min protocol	Moderate	Yes
Streptokinase	Low	IV infusion	Fixed dose, 60 min	Moderate–high	No
Urokinase	Low	IV infusion	Weight-based	Moderate–high	Rarely used