obstructive vs preventative

obstructive is not a noun while preventative is a noun.

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

obstructive (noun)	preventative (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

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