title: Efficacy and safety of fixed-dose oral sildenafil.
authors.forename: C B
authors.initials: CB
authors.lastname: Williams
mesh_terms: D007172:Erectile Dysfunction / Q000175:diagnosis* / Q000188:drug therapy* / Q000209:etiology; D006801:Humans; D008297:Male; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage*; D010879:Piperazines / Q000008:administration & dosage*; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate