Poisoning and STOPP/START Quiz

See Opioids. Option C is correct because naloxone has a short duration of action, while many opioids last much longer, so the antidote can wear off while the opioid is still active. Opioid overdose gives the classic triad of pinpoint pupils, respiratory depression and reduced consciousness. Naloxone is an opioid antagonist: it occupies the opioid receptors and blocks the opioid from acting on them, which is why her breathing has improved. The aim is to restore adequate breathing, not to wake her fully, because complete reversal in someone who uses opioids regularly can cause acute withdrawal. When the naloxone wears off, which happens sooner than with long-acting opioids such as methadone, breathing can fail again. She therefore needs close monitoring, with further naloxone given as her breathing slows. If repeated doses are needed, the BNF advises giving naloxone as a continuous intravenous infusion instead, with the rate adjusted to her respiratory rate and level of consciousness. As a rule, short-acting antidote plus long-acting poison means you should expect to repeat the antidote.

• Duration: naloxone is short-acting, while many opioids last longer, so the antidote can wear off.
• Consequence: breathing can fail again once the naloxone wears off.
• Management: close monitoring with further naloxone, or a continuous intravenous infusion if repeat doses are needed.