Lidocaine and propranolol interactions include competing for the same metabolic enzyme. True or False?

Lidocaine and propranolol interactions include competing for the same metabolic enzyme. True or False?

• A. True
• B. False
• C. Not specified
• D. No interaction

Answer: (A)

Enzyme-based drug interactions occur when two drugs rely on the same hepatic enzyme for metabolism. Lidocaine is mainly cleared by hepatic CYP1A2 (and CYP3A4), while propranolol is extensively metabolized by CYP1A2 (along with other enzymes like CYP2D6). Because they both use CYP1A2, they can compete for the same enzymatic pathway. This competition can slow metabolism, raise plasma levels of one or both drugs, and increase the risk of adverse effects, such as lidocaine toxicity or exaggerated beta-blockade. So the statement is true.

Enzyme-based drug interactions occur when two drugs rely on the same hepatic enzyme for metabolism. Lidocaine is mainly cleared by hepatic CYP1A2 (and CYP3A4), while propranolol is extensively metabolized by CYP1A2 (along with other enzymes like CYP2D6). Because they both use CYP1A2, they can compete for the same enzymatic pathway. This competition can slow metabolism, raise plasma levels of one or both drugs, and increase the risk of adverse effects, such as lidocaine toxicity or exaggerated beta-blockade. So the statement is true.