What medication is usually administered for a pulmonary embolus?

In the management of a pulmonary embolus, the primary goal is to dissolve the blood clot that is obstructing the pulmonary artery. Streptokinase is a thrombolytic agent, meaning it can break down clots by activating the body's fibrinolytic system, thereby restoring blood flow. This is crucial in cases of pulmonary embolism, where timely dissolution of the clot can significantly improve outcomes and reduce the risk of complications.

The other options do not address the specific nature of a pulmonary embolus. Antitubercular agents are used to treat tuberculosis and not related to clotting disorders. Antibiotics are appropriate for treating infections, which may occur post-embolism but do not help in managing the embolic event directly. Similarly, pneumothorax management pertains to the treatment of air in the pleural space and is unrelated to the treatment of blood clots in the pulmonary circulation. Thus, the use of streptokinase stands out as the correct choice for effectively treating a pulmonary embolus.