title: Clinical safety of oral sildenafil citrate (VIAGRA) in the treatment of erectile dysfunction.
abstract: Sildenafil citrate has been shown to be effective in a wide range of patients with erectile dysfunction and has been approved in the United States for this indication. The overall clinical safety of oral sildenafil, a potent inhibitor of phosphodiesterase type 5, in the treatment of erectile dysfunction was evaluated in more than 3700 patients (with a total of 1631 years of exposure worldwide). Safety and tolerability data were analysed from a series of double-blind, placebo-controlled studies and from 10 open-label extension studies of sildenafil in the treatment of erectile dysfunction. A total of 4274 patients (2722 sildenafil, 1552 placebo; age range 19-87 y) received double-blind treatment over a period of up to six months' duration, and 2199 received long-term, open-label sildenafil for up to 1 y. The most commonly reported adverse events (all causes) were headache (16% sildenafil, 4% placebo), flushing (10% sildenafil, 1% placebo), and dyspepsia (7% sildenafil, 2% placebo) and they were predominantly transient and mild or moderate in nature. These adverse events reflect the pharmacology of sildenafil as a phosphodiesterase type 5 inhibitor. No cases of priapism were reported. The rate of discontinuation due to adverse events (all causes) was comparable for patients treated with sildenafil (2.5%) and placebo (2.3%). In open-label extension studies, 90% of patients completed long-term sildenafil treatment, with only 2% withdrawing due to adverse events. Sildenafil is a well-tolerated oral treatment for erectile dysfunction.
authors.affiliation: Department of Urology, Queen's University, Kingston General Hospital, Ontario, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Morales
authors.forename: C
authors.initials: C
authors.lastname: Gingell
authors.forename: M
authors.initials: M
authors.lastname: Collins
authors.forename: P A
authors.initials: PA
authors.lastname: Wicker
authors.forename: I H
authors.initials: IH
authors.lastname: Osterloh
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000139:chemically induced; D004311:Double-Blind Method; D004415:Dyspepsia / Q000139:chemically induced; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D007172:Erectile Dysfunction / Q000188:drug therapy*; D005483:Flushing / Q000139:chemically induced; D006261:Headache / Q000139:chemically induced; D006801:Humans; D008875:Middle Aged; D010879:Piperazines / Q000009:adverse effects / Q000627:therapeutic use*; D010919:Placebos; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones
chemical_list: D004791:Enzyme Inhibitors; D010879:Piperazines; D010919:Placebos; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate; D015106:3',5'-Cyclic-GMP Phosphodiesterases