<unk> (suppository) is a endocrine-metabolic agent ,  erectile dysfunction agent  and genitourinary agent that is FDA approved for the treatment of erectile dysfunction due to neurogenic, vasculogenic, psychogenic, or mixed etiology.   Common adverse reactions include bradyarrhythmia, hypotension, tachycardia, flushing, urethral discomfort, fibrosis of penis, pain in penis, pain in testicle and fever.
Alprostadil 
Iofendylate
Epoprostenol
Bosentan
Endralazine
Guanoxan
Papaverine
Minoxidil 