Yes, CLOZAPINE is a Scrabble word!

Letter values in Scrabble US: C 3, L 1, O 1, Z 10, A 1, P 3, I 1, N 1, E 1.

Is it a valid word?

CLOZAPINE is a valid word in the official Scrabble dictionary (US) and the UK Scrabble Dictionary, but not in Words with Friends (ENABLE).

an antipsychotic drug (trade name Clozaril) used as a sedative and for treatment-resistant schizophrenia; know to have few side effects

Not playable in Scrabble US: CLOZARIL.