title: Viagra turns 5.
authors.forename: Christine
authors.initials: C
authors.lastname: Gorman
mesh_terms: D004345:Drug Industry / Q000191:economics; D004465:Economic Competition; D006801:Humans; D008297:Male; D010879:Piperazines / Q000191:economics; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D014481:United States
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate