<prompt> Not used for erectile dysfunction -Beta blockersSiledenafilPG-E,Papaverine  <response>: Ans. is a i.e., b-blockers Drugs used for erectile dysfunctionPhosphodiesterase-5 inhibitors Siledenafil, Todafil, Vardenafil.o By inhibiting PDE-5, these drugs prevent degradation of cGMP and potentiate the action of NO.o These are the DOC for pharmacological therapy of erectile dysfunction.Alprastadil Prostaglandin Elo It is a powerful vasodilator.o It acts by increasing arterial inflow by vasodilation and reducing outflow by contracting the carporal smooth muscle that occludes draining venules.o It is the DOC for patients not responding to PDE-5 inhibitors.o It is directly injected into corpora cavernosa.Papaverineo It is a nonspecific phosphodiesterase inhibitor.o Injection of papaverine with or without phentolamine into corpus cavemosum produces penile tumiscence to permit intercourse.o Repeated injection can cause penile fibrosis.Androgenso Can be used when androgen deficiency is demonstrated to be responsible for the loss of libido and erectile dysfunction.Apomorphine Laurence 9the p. 546o A dopamine antagonist, is given by subcutaneous injection. 