A nurse is caring for an elderly patient who has been taking diphenhydramine (Benadryl) for insomnia. Which central nervous system effect is the nurse most likely to observe in this patient?

No CNS effects, diphenhydramine doesn't cross the blood brain barrier.

Diphenhydramine is known to cause seizures in elderly clients

Diphenhydramine can cause confusion and sedation in an elderly client

Diphenhydramine can cause euphoria in an elderly client