<prompt> Which of the following is not used in the treatment of pulmonary hypertension?Calcium channel blockersAlpha blockersProstacyclinsEndothelin receptor antagonists  <response>: Ans. B Alpha blockersRef: CMDT 2010381Management of Idiopathic Pulmonary HypertensionIf the patient responds to vasodilators, then calcium channel blockers including amlodipine, diltiazem, and nifedipine are the first-line therapy.Other drugs that can be used are:-Phosphodiesterase inhibitors e.g. sildenafil-Prostacyclin analogs e.g. epoprostenol-endothelin receptor blockers e.g. bosentan 