mid-15c., "to poison" (obsolete), from Medieval Latin intoxicatus, past participle of intoxicare "to poison," from in- "in" (from PIE root *en "in") + Latin toxicare "to poison," from toxicum "poison" (see toxic). Meaning "make drunk" first recorded 1570s (implied in intoxicated). Figurative sense "excite to a high pitch of feeling" is attested from 1590s. Related: Intoxicating.
Others are reading
<a href="https://www.etymonline.com/word/intoxicated">Etymology of intoxicated by etymonline</a>
Harper, D. (n.d.). Etymology of intoxicated. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/intoxicated