Question:medium
All of the following statements about phenytoin are true, except:
All of the following statements about phenytoin are true, except:
Show Hint
Phenytoin affects blood sugar, but in which direction does it push insulin?
Updated On: Jun 24, 2026
- Follows saturation kinetics
- Is teratogenic
- Is highly protein bound
- Stimulates insulin secretion
Show Solution
The Correct Option is D
Solution and Explanation
The stem hunts for the one wrong fact among true ones, so each claim about phenytoin needs checking.
Saturation kinetics is correct: phenytoin's elimination enzymes saturate at normal doses, so the drug switches to zero-order handling and plasma levels can climb sharply after a small dose increase. Teratogenicity is correct too, as phenytoin in pregnancy produces fetal hydantoin syndrome with facial, nail, and growth defects. High protein binding is also right, with roughly $90\%$ of the drug bound to albumin, which matters when albumin is low because free drug rises.
The remaining statement says phenytoin stimulates insulin secretion. This is the false one. Phenytoin in fact suppresses insulin release and tends to raise blood glucose, so claiming it boosts insulin is exactly backwards. That makes it the answer.
\[\boxed{\text{Stimulates insulin secretion}}\]
Saturation kinetics is correct: phenytoin's elimination enzymes saturate at normal doses, so the drug switches to zero-order handling and plasma levels can climb sharply after a small dose increase. Teratogenicity is correct too, as phenytoin in pregnancy produces fetal hydantoin syndrome with facial, nail, and growth defects. High protein binding is also right, with roughly $90\%$ of the drug bound to albumin, which matters when albumin is low because free drug rises.
The remaining statement says phenytoin stimulates insulin secretion. This is the false one. Phenytoin in fact suppresses insulin release and tends to raise blood glucose, so claiming it boosts insulin is exactly backwards. That makes it the answer.
\[\boxed{\text{Stimulates insulin secretion}}\]
Was this answer helpful?
0
