<prompt> Which of the following is not used in the treatment of pulmonary hypeension?Calcium channel blockersAlpha blockersProstacyclinsEndothelin receptor antagonists  <response>: Alpha blocker like prazosin, doxazosin, tamsulosin have no role in pulmonary hypeension Prostacyclin I2 analogs, endothelin antagonists like macicentan are used in pul.HTN CCBs- cause vasodilation thereby providing benefit in Pul. HTN sildenafil, tadalafil- PDE5 inhibitors are also used Ref: KD Tripathi 8th ed 