Morphine

Opioid Agonist

Drug Class: Opioid Agonist
Mechanism of Action (MOA): µ-opioid receptor agonist → ↓ pain transmission and altered pain perception.
Black Box Warning: Addiction, abuse, and misuse; life-threatening respiratory depression; fatal with benzodiazepines or alcohol.
Clinical Notes: Severe pain. Respiratory depression, constipation (no tolerance develops), miosis, histamine release; active metabolite accumulates in renal failure. Reverse with naloxone.
Source: FDA label (DailyMed)

Sources

Reviewed June 2026

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