Yes, THIAZIDE is a Scrabble word!

Letter values in Scrabble US: T 1, H 4, I 1, A 1, Z 10, I 1, D 2, E 1.

Is it a valid word?

THIAZIDE is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

any of a group of drugs commonly used as diuretics in the treatment of hypertension; they block the reabsorption of sodium in the kidneys