title: Effect of sildenafil (Viagra) on cerebral blood flow velocity: a pilot study.
abstract: Sildenafil (Viagra) is a selective inhibitor of the cyclic guanosine monophosphate (cGMP) specific phosphodiesterase 5 (PDE5) used for the oral treatment of male erectile dysfunction due to vasodilation. However, assessment of direct effects of sildenafil on cerebral arteries is unknown. The aim of this present experiment is to measure the possible changes in blood flow velocity of the middle cerebral artery after the administration of sildenafil and a placebo. Blood-flow velocity changes of the middle cerebral artery were measured before and 1 to 2 h after the administration of the drug. Neither the intake of sildenafil nor the application of placebo resulted in any significant changes in blood flow velocity of the right middle cerebral artery. The next step for future experiments will be in vitro measurement of the diameters of the cerebral arteries under the influence of sildenafil and in vivo measurement of carbon dioxide and cerebral blood flow velocity during sexual stimulation after sildenafil intake instead of under resting conditions.
authors.affiliation: Department of Clinical Psychiatry and Psychotherapy, Medical School Hannover, 30625 Hannover, Germany.
authors.forename: Anouscheh
authors.initials: A
authors.lastname: Arnavaz
authors.forename: Andreas
authors.initials: A
authors.lastname: Aurich
authors.forename: Karin
authors.initials: K
authors.lastname: Weissenborn
authors.forename: Uwe
authors.initials: U
authors.lastname: Hartmann
authors.forename: Hinderk M
authors.initials: HM
authors.lastname: Emrich
authors.forename: Udo
authors.initials: U
authors.lastname: Schneider
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D001921:Brain / Q000098:blood supply*; D002560:Cerebrovascular Circulation / Q000187:drug effects* / Q000502:physiology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004453:Echoencephalography; D006801:Humans; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010865:Pilot Projects; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology*; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D018608:Ultrasonography, Doppler; D014664:Vasodilation / Q000187:drug effects
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate