Dexmedetomidine is an alpha(2)-adrenoreceptor agonist that, in spite of its potent sedative, amnesic, and analgesic properties, has minimal respiratory depressant effect. Even at doses adequate for general anaesthesia, it does not cause central apnoea. Thus, it has been claimed that "combining alpha(2)-agonists with opiate narcotics or non-steroidal anti-inflammatory drugs can enhance the analgesic efficacy without increasing the respiratory depressant effect of the latter" and "the combination of alpha(2)-adrenoceptor agonists with opioids does not lead to further ventilatory depression". We present a case of central apnoea after general anaesthesia that included opioids and dexmedetomidine, and remind the readers that in susceptible patients, dexmedetomidine may cause life-threatening respiratory depression through potentiation of co-administered central nervous system depressants.
