A nurse is caring for an 82-year-old male with a history of mild kidney dysfunction who is recently admitted to the hospital for an unwitnessed fall. The nurse noted that the client had been taking cimetidine (Tagamet HB) at the maximum dosage for 2 months. Which of the following are complications of this cimetidine (Tagamet HB) that contributed to his admission? (Select All That Apply.)

A. Restlessness is not a common side effect of cimetidine. Neurological side effects typically involve sedation or confusion rather than hyperactivity. B. Lethargy is a potential adverse effect of cimetidine, especially in older adults or those with renal dysfunction, due to the drug’s impact on the central nervous system. C. Increased libido is not associated with cimetidine. In fact, it may cause decreased libido and sexual dysfunction in some cases. D. Confusion is a known complication of cimetidine, particularly in elderly clients with impaired renal function, as the drug can accumulate in the body and affect the brain.