preventative vs obstructive

preventative is a noun but obstructive is not a noun.

Word	Noun	Adjective	Verb	Adverb
preventative	Yes	Yes	No	No
obstructive	No	Yes	No	No

preventative (noun)	obstructive (noun)
remedy that prevents or slows the course of an illness or disease
an agent or device intended to prevent conception
any obstruction that impedes or is burdensome

preventative (adjective)	obstructive (adjective)
tending to prevent or hinder	preventing movement
preventing or contributing to the prevention of disease