antihistamine vs medication

antihistamine and medication both are nouns.

Word	Noun	Adjective	Verb	Adverb
antihistamine	Yes	No	No	No
medication	Yes	No	No	No

As nouns, medication is a hypernym of antihistamine; that is, medication is a word with a broader meaning than antihistamine:

antihistamine: a medicine used to treat allergies and hypersensitive reactions and colds; works by counteracting the effects of histamine on a receptor site
medication: (medicine) something that treats or prevents or alleviates the symptoms of disease

Other hypernyms of antihistamine include medicament, medicinal drug, medicine.

antihistamine (noun)	medication (noun)
a medicine used to treat allergies and hypersensitive reactions and colds; works by counteracting the effects of histamine on a receptor site	the act of treating with medicines or remedies
	(medicine) something that treats or prevents or alleviates the symptoms of disease