Assertion: viagra | /r/HasProperty | approved
Facets:
value: a few years
type: TEMPORAL
Source sentences:
text: According to a recent study of erection side effects during the decade from 1998 (the year Viagra was approved) through 2007, Viagra has been implicated in at least 1,824 deaths mostly from heart attacks.
text: A few years after Viagra was approved, two other ED meds — Cialis (tadalafil) and Levitra (vardenafil)