A 68-year-old woman comes to the physician because of a 3-month history of increased frequency of falls. She has type II diabetes mellitus, hypertension, osteopenia, and gastroesophageal reflux due to diabetic gastroparesis. Medications are lisinopril, metformin, alendronate, metoclopramide, and cimetidine. Physical examination shows decreased spontaneous movement in all extremities and cogwheel rigidity of both wrists. On gait testing, she walks in short steps. Which of the following is the most appropriate next step in management?
Discontinue alendronate
Discontinue cimetidine
Discontinue metoclopramide
Add carbidopa-levodopa
Add ropinerole
