Q77
Single choice
Since cimetidine inhibits CYP2D6, less amphetamine will probably need to be given since it will not be able to be metabolized as readily.
Most drug interactions are like this: one drug inhibits or competes with the same CYP450 as another drug.
The end result is that higher concentrations of one, or both, drugs are present, leading to potential toxicity.
A patient is taking cimetidine for a stomach ulcer. This drug inhibits CYP2D6. The patient is now prescribed amphetamine for narcolepsy. Amphetamine is metabolized by CYP2D6.
What would you predict?