Pyridium vs pain pill

Pyridium and pain pill both are nouns.

Word	Noun	Adjective	Verb	Adverb
Pyridium	Yes	No	No	No
pain pill	Yes	No	No	No

As nouns, pain pill is a hypernym of Pyridium; that is, pain pill is a word with a broader meaning than Pyridium:

Pyridium: analgesic (trade name Pyridium) used to treat urinary tract infections
pain pill: a medicine used to relieve pain

Other hypernyms of Pyridium include analgesic, anodyne, painkiller.

Pyridium (noun)	pain pill (noun)
analgesic (trade name Pyridium) used to treat urinary tract infections	a medicine used to relieve pain