'barbiturate-associated' originates from Modern English, specifically the words 'barbiturate' and 'associated', where 'barbiturate' meant 'a derivative of barbituric acid (a class of sedative-hypnotic drugs)' and 'associated' meant 'joined or connected'.

'barbiturate' entered English in the 19th century (from German/French formations relating to barbituric acid) and 'associate' comes from Latin 'associare' via Old French and Middle English; the compound form 'barbiturate-associated' is a modern English formation created by combining the noun and the past-participle adjective.

Initially, 'barbiturate' referred specifically to barbituric acid or its salts; over time it came to denote the class of drugs derived from that acid. The compound now conveys the modern medical sense 'related to or resulting from barbiturate use.'