'barbiturate-related' originates from modern English, specifically the compound of the noun 'barbiturate' and the adjective 'related', where 'barbiturate' refers to the class of drugs derived from barbituric acid and 'related' meant 'connected to'.

'barbiturate' entered English in the 19th century from Neo-Latin 'barbituricus' (from barbituric acid), while 'related' comes from Old French/Latin (Latin 'relatus', past participle of 'referre'). In modern English these elements were combined to form the compound adjective 'barbiturate-related'.

Initially the parts referred separately to the chemical class ('barbiturate') and the notion of connection ('related'); over time the compound came to mean specifically 'connected with or stemming from barbiturates'.