Question

Quinidine is prescribed to a client with cardiac arrhythmia. When documenting the client's drug history, the nurse inquires about the concomitant use of any other drug. Which of the following drugs when given concomitantly may cause an increase in serum quinidine levels?

A) Cimetidine
B) Rifampin
C) Hydantoins
D) Nifedipine

Answer 1

Cimetidine can cause an increase in serum quinidine levels due to the inhibition of quinidine metabolism through the cytochrome P450 enzyme system.

Step-by-step explanation:

When quinidine is prescribed to a client with cardiac arrhythmia and the nurse inquires about the concomitant use of any other drug, Cimetidine is the correct answer. Cimetidine, a drug that inhibits the cytochrome P450 enzyme system, may cause an increase in serum quinidine levels by inhibiting its metabolism. Other options like Rifampin, Hydantoins, and Nifedipine are less likely to interact in this manner. It's important for healthcare providers to be mindful of drug interactions like this to avoid causing potential adverse effects from elevated drug levels.