<prompt> A 28-year-old male patient is brought to casualty in comatose state with pin-point pupils, reduced respira- tory rate and bradycardia. Most likely diagnosis: UPSC 09; CMC Vellore 14Tricyclic antidepressant poisoningOpioid poisoningBenzodiazepine poisoningOrganophosphorus poisoning  <response>: Ans. Opioid poisoning 