Case 1: M.R. is a 75-year-old woman who is being treated by a physical therapist post hip replacement. Her medications include desipramine for chronic pain. She takes diphenhydramine to help her sleep. She is then started on hyoscyamine for diarrhea. She now is showing worsening memory problems and disorientation.

1. What do these drugs have in common that might lead to this presentation?

2. How do these drugs act to produce these symptoms?

Case 2: Confusion due to benzodiazepine A 75-year-old man is brought to the emergency room by his daughter. She states that over the past few days his cognitive abilities have shown a marked decrease. He now appears disoriented. His medical history includes hypertension, hypercholesterolemia, and atrial fibrillation. His medications include simvastatin, quinapril, and warfarin. He has recently been complaining of difficulty sleeping and has been started on a long-acting benzodiazepine, alprazolam.

1. How does addition of benzodiazepine cause disorientation?

2. What role might the patient's age play in the metabolism of his medications?

3. How might the physician change the prescription to avoid these side effects