Assertion: viagra | /r/HasProperty | the trade name
Facets:
value: for a drug
type: TRANSITIVE-OBJECT
Source sentences:
text: Viagra is the trade name for a drug called Sildenafil.
text: Some experts consider Terrett as the father of Viagra as he was named in the 1991 British patent for Sildenafil (trade name Viagra) as a possible heart medicine.