Which medication reduces MAC?

Which medication reduces MAC?

• A. Captopril
• B. Minoxidil
• C. Clonidine
• D. Labetalol

Answer: (C)

Some drugs can lower the amount of inhaled anesthetic needed by providing central sedation and analgesia. Clonidine does this best because it is an alpha-2 adrenergic agonist that reduces central sympathetic outflow and offers analgesia and sedation. This CNS depressant effect lowers the MAC of volatile anesthetics in a dose-dependent way, meaning less anesthetic is required to prevent movement. The other options don’t have a meaningful MAC-sparing effect. Captopril and minoxidil act mainly on blood pressure through peripheral mechanisms and don’t provide the CNS depression that reduces inhaled anesthetic requirements. Labetalol can lower blood pressure via beta and alpha blockade but isn’t recognized for reliably decreasing MAC.

Some drugs can lower the amount of inhaled anesthetic needed by providing central sedation and analgesia. Clonidine does this best because it is an alpha-2 adrenergic agonist that reduces central sympathetic outflow and offers analgesia and sedation. This CNS depressant effect lowers the MAC of volatile anesthetics in a dose-dependent way, meaning less anesthetic is required to prevent movement.

The other options don’t have a meaningful MAC-sparing effect. Captopril and minoxidil act mainly on blood pressure through peripheral mechanisms and don’t provide the CNS depression that reduces inhaled anesthetic requirements. Labetalol can lower blood pressure via beta and alpha blockade but isn’t recognized for reliably decreasing MAC.