A worked case: the Libby Zion death (1984) as a phenelzine + meperidine interaction

A case report is most useful when the mechanism is clear in hindsight. The 1984 death of Libby Zion in New York is a documented, consequential example — it reshaped US residency hours — and read pharmacologically it is a textbook MAOI interaction. What was taken (from the public record) Libby Zion, 18, was admitted agitated and febrile. She was a patient on phenelzine (Nardil), an irreversible non-selective MAOI. In hospital she was given meperidine (pethidine) for shivering/agitation. The interaction Meperidine is not just an opioid — it is serotonergic (it inhibits serotonin reuptake). Meperidine + an MAOI is one of the oldest and most lethal documented serotonin-toxicity combinations; it is specifically contraindicated. She developed hyperthermia and died of cardiac arrest. Why it is the canonical teaching case - It is the real-world version of the serotonin-syndrome thread on Pharmacology & Interactions: MAOI + serotonergic agent, onset in hours, hyperthermia. - The "what else was in the system" field was the whole case: the home medication (phenelzine) was the lethal variable, and the hospital drug (meperidine) was chosen without it being accounted for. - It drove the Bell Commission and the 80-hour resident work-week reforms — a systems response to an interaction that a drug-interaction check would have caught. Sources: Brensilver JM, review of the Libby Zion case; Gillman PK, Br J Anaesth 2005 (MAOIs and opioid/serotonin toxicity); public court record (Zion v. New York Hospital). The safer opioids with an MAOI on record are those without serotonin activity (e.g. morphine), which is itself a mechanism lesson. Mechanism: https://wiki.soapbox.community/wiki/Monoamine_Oxidase_Inhibitors_and_Neurotransmitter_Systems