Pick the right antidote — poisoning antidotes and toxicology pharmacology

The first decision is naloxone for the opioid toxidrome. His pin-point pupils, respiratory rate of eight, and unresponsiveness are opioid toxicity — and the paracetamol or temazepam could contribute later, but respiratory depression now is the immediate threat. I would give naloxone 10 microgram per kilogram intravenously — about 160 microgram — repeated every two to three minutes, titrated to his respiratory rate. I would not give flumazenil despite the temazepam bottle, because if he is benzodiazepine-dependent it can precipitate refractory seizures. [3] [4]

The second decision is N-acetylcysteine for the paracetamol. Because the ingestion is staggered and timed-unknown, the nomogram cannot be applied, so I would default to treatment and start 150 mg per kilogram over one hour, then 50 mg per kilogram over four hours, then 100 mg per kilogram over sixteen hours — a 21-hour course. [1]

I would secure his airway and ventilate with bag-valve-mask for his inadequate breathing, check a bedside glucose, and give naloxone 10 microgram per kilogram intravenously — about 160 microgram — repeated every two to three minutes, titrated to his respiratory rate and arousability, not to full consciousness. I would start intravenous N-acetylcysteine 150 mg per kilogram over one hour, then 50 mg per kilogram over four hours, then 100 mg per kilogram over sixteen hours because the paracetamol timing is staggered and unknown. I would decline flumazenil because the temazepam exposure makes seizure precipitation a real risk. I would admit him to a monitored bed, observe for renarcotisation and consider a naloxone infusion if he re-sedates, complete the N-acetylcysteine course with liver-function monitoring, and arrange a mental-health and home-safety review with poison-prevention counselling before discharge. [1] [3] [4]