Morphine

The exam loves the “which assessment before you give it” stem, and the answer hinges on respiratory rate — the commonly taught rule is to hold the dose and notify the provider if RR is below 12/min (some protocols use 8–10, so follow facility policy). Note the trap: the safest action is to withhold the dose, not to give it and monitor afterward. Sedation level is the other priority parameter, because rising sedation precedes respiratory depression. In the pulmonary-edema scenario, also watch for hypotension. The overdose triad to recognize is pinpoint pupils, respiratory depression, and CNS depression (coma).

The sharpest contrast is with naloxone: morphine is the agonist that causes the depression; naloxone is the antagonist that reverses it. The classic miss is that naloxone’s short duration can outlast a single dose, so re-sedation can recur as it wears off — keep monitoring and be ready to redose. Don’t confuse opioid-induced respiratory depression (give naloxone) with benzodiazepine oversedation (give flumazenil). Memory hook: “morphine drops the rate, naloxone brings it back.”