A nurse should question an order for meperidine hydrochloride (Demerol) for a client who is receiving which of these medications?

• A. An anti-anxiety medication
• B. A monoamine oxidase (MAO) inhibitor
• C. An antihypertensive medication
• D. A diuretic

Answer: (B)

Meperidine should not be given to a patient taking a monoamine oxidase inhibitor because MAOIs prevent the breakdown of serotonin and other monoamines. Meperidine can increase serotonin levels, and when combined with an MAOI, this can lead to a dangerous rise in serotonin and sympathetic activity. The result can be a life-threatening reaction such as serotonin syndrome and a hypertensive crisis, with symptoms like agitation, severe autonomic instability, hyperthermia, seizures, and even coma. Because of this, the clinician should question the order if the patient is on an MAOI. Other listed medications may cause added sedation or other effects, but they do not create this specific high-risk interaction with meperidine.