A 75-year-old woman with a history of diabetes, depression and a 2-year history of gradually progressive decline in memory, language and judgment presents with a syncopal episode. Her heart rate is 36. Which of the following medications would most likely be responsible for the bradycardia?
A. amitriptyline
B. donepezil
C. ginkgo biloba
D. memantine
E. metformin
