Three drugs (X, Y, Z) were tested for their ability to elicit a downstream response in cells bearing a particular receptor. Dose-response curves are shown.
Which drug is a partial agonist?
- A
Drug Y, because it shifts the curve right.
- Bcheck_circle
Drug Z, because its maximum response is below 100 percent.
- C
All three are full agonists.
- D
Drug X, because it is the most potent.
Explanation
Partial agonists cannot achieve maximal response (lower efficacy) regardless of dose. Drug Z plateaus below 100 percent.