title: Direct sale of sildenafil (Viagra) to consumers over the Internet.
authors.affiliation: University of Pennsylvania School of Medicine, Philadelphia 19104-6021, USA.
authors.forename: K
authors.initials: K
authors.lastname: Armstrong
authors.forename: J S
authors.initials: JS
authors.lastname: Schwartz
authors.forename: D A
authors.initials: DA
authors.lastname: Asch
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D003132:Commerce / Q000592:standards / Q000706:statistics & numerical data*; D011307:Drug Prescriptions / Q000592:standards / Q000706:statistics & numerical data*; D007172:Erectile Dysfunction / Q000175:diagnosis / Q000188:drug therapy*; D006801:Humans; D020407:Internet / Q000592:standards / Q000706:statistics & numerical data*; D008297:Male; D008487:Medical History Taking / Q000706:statistics & numerical data; D009819:Office Visits; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D011795:Surveys and Questionnaires; D014481:United States
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate; D015106:3',5'-Cyclic-GMP Phosphodiesterases