A nurse is assessing a client after administering phenytoin IV bolus for a seizure. Which of the following should the nurse identify as an adverse effect of this medication?

The correct answer is D: Hypotension. Phenytoin can cause hypotension as an adverse effect due to its vasodilatory properties. The drug can cause a decrease in blood pressure, leading to symptoms such as dizziness and lightheadedness. This adverse effect is important for the nurse to recognize as it can potentially lead to complications such as falls in the client.

A: Hypoglycemia is not a common adverse effect of phenytoin.
B: Bradycardia is not a typical adverse effect of phenytoin.
C: Red man syndrome is associated with vancomycin, not phenytoin.
Summary: Phenytoin is more likely to cause hypotension as an adverse effect, rather than hypoglycemia, bradycardia, or red man syndrome.