If a patient on phenelzine has consumed alcohol and presents to the ED, what should be checked?

• A. Check blood sugar
• B. Check blood pressure
• C. Check liver function
• D. Check oxygen saturation

Answer: (B)

When a patient on phenelzine, an MAOI, has alcohol, the main risk is a hypertensive crisis from excessive sympathetic activity. Phenelzine blocks the breakdown of norepinephrine, so substances that raise catecholamine levels or interact with tyramine can push blood pressure up sharply. The priority in the ED is to check the blood pressure and monitor it closely to detect any dangerous hypertension early. Serial BP readings guide immediate management to prevent end-organ damage. While other labs like blood sugar, liver function, or oxygen saturation are part of general care, they do not address the acute, life-threatening risk posed by MAOI-alcohol interaction as directly as blood pressure monitoring does.