Which analgesic is contraindicated in patients taking monoamine oxidase inhibitors due to risk of a severe hypertensive reaction?

Which analgesic is contraindicated in patients taking monoamine oxidase inhibitors due to risk of a severe hypertensive reaction?

• A. Fentanyl
• B. Meperidine
• C. Morphine
• D. Hydromorphone

Answer: (B)

The main idea is that monoamine oxidase inhibitors (MAOIs) block the breakdown of monoamines like norepinephrine. Some opioids can provoke additional release of these monoamines, and when MAOIs are present, this can push norepinephrine levels up too high, triggering a dangerous hypertensive reaction. Meperidine is the analgesic with a notable effect: it strongly releases norepinephrine from nerve endings. With MAOIs inhibiting breakdown, this surplus norepinephrine can cause a severe rise in blood pressure and related symptoms. The risk of this hypertensive crisis is why meperidine is avoided in patients taking MAO inhibitors. In addition, its metabolite normeperidine can accumulate and contribute to CNS excitation and seizures, especially with renal impairment, which adds to its toxicity in this context. Fentanyl, morphine, and hydromorphone do not produce the same level of norepinephrine release or monoamine interactions with MAOIs, so they are not associated with the same hypertensive risk and are considered safer choices for analgesia in patients on MAO inhibitors.

The main idea is that monoamine oxidase inhibitors (MAOIs) block the breakdown of monoamines like norepinephrine. Some opioids can provoke additional release of these monoamines, and when MAOIs are present, this can push norepinephrine levels up too high, triggering a dangerous hypertensive reaction.

Meperidine is the analgesic with a notable effect: it strongly releases norepinephrine from nerve endings. With MAOIs inhibiting breakdown, this surplus norepinephrine can cause a severe rise in blood pressure and related symptoms. The risk of this hypertensive crisis is why meperidine is avoided in patients taking MAO inhibitors. In addition, its metabolite normeperidine can accumulate and contribute to CNS excitation and seizures, especially with renal impairment, which adds to its toxicity in this context.

Fentanyl, morphine, and hydromorphone do not produce the same level of norepinephrine release or monoamine interactions with MAOIs, so they are not associated with the same hypertensive risk and are considered safer choices for analgesia in patients on MAO inhibitors.