**Question:** Thrombolytic therapy with streptokinase is contraindicated in all of the following except

A. Acute coronary syndromes
B. Acute pulmonary embolism
C. Acute stroke due to large vessel occlusion
D. Subarachnoid hemorrhage

**Correct Answer:** .

**Core Concept:** Thrombolytic therapy is a method used to dissolve blood clots by administering drugs that break down clot-forming substances, clotting factors, or fibrin. Streptokinase is a recombinant form of streptokinase, which is a serine protease that directly activates plasminogen to plasmin, a fibrinolytic enzyme that breaks down fibrin, thus dissolving blood clots. Thrombolytic therapy is indicated in conditions where clot formation is causing significant morbidity or mortality.

**Why the Correct Answer is Right:** Streptokinase is contraindicated in most situations due to the risk of intracranial hemorrhage and other complications. Dissolving a clot in a subarachnoid hemorrhage (D) carries a high risk of worsening the condition by causing a massive intracranial hemorrhage, leading to severe brain damage or death.

**Why Each Wrong Option is Incorrect:**

A. Acute coronary syndromes (e.g., MI) are often managed with thrombolytic therapy, such as streptokinase, to restore coronary blood flow and prevent myocardial infarction.

B. Acute pulmonary embolism (PE) can lead to right ventricular failure, shock, and death. Thrombolytic therapy with streptokinase is indicated in PE to dissolve the clot and improve blood flow to the lungs, reducing the severity of the condition.

C. Acute stroke due to large vessel occlusion (e.g., occlusion of the middle cerebral artery) can cause irreversible brain damage or death. However, in certain cases, thrombolytic therapy with streptokinase can be considered if the risk-benefit ratio is favorable and the patient is within the therapeutic time window.

**Clinical Pearl:** In carefully selected patients with acute ischemic stroke, thrombolytic therapy with streptokinase or other thrombolytic agents can improve clinical outcomes. However, this should be done under the supervision of a trained physician and according to specific guidelines to minimize risks and maximize benefits.