Concomitant administration of this drug with organic nitrates is contraindicated due to marked potentiation of vasodilatory action leading to profund hypotension. This drug is:: (A) Propanolol, (B) Fluoxetine, (C) Hydrochlorothiazide, (D) Sildenafil
Answer is D. (Ref: KDT 6/e p525) Nitrates release No, that acts by increasing cGMP. Phosphodiesterase inhibitors like sildenafil inhibits the breakdown of cGMP. Concomitant use of these two drugs may result in profound hypotension.