title: What to do if Viagra won't do.
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors; D000527:Alprostadil / Q000008:administration & dosage; D004343:Drug Implants / Q000008:administration & dosage; D007172:Erectile Dysfunction / Q000628:therapy*; D006801:Humans; D007267:Injections / Q000379:methods; D008297:Male; D010410:Penile Erection; D015917:Penile Prosthesis; D010879:Piperazines / Q000627:therapeutic use; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D004343:Drug Implants; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D000527:Alprostadil