About: http://webisa.webdatacommons.org/333549780

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Medications used to treat erectile dysfunction, such as sildenafil (Viagra??), vardenafil (Levitra??), and tadalafil (Cialis??), improve erectile function by inhibiting the PDE5 enzyme, allowing an erection to persist (Kolodny 2011).
http://www.w3.org/ns/prov#wasQuotedFrom	lef.org