Anticholinergic Burden and Falls in an Older Adult With OAB
Ms. K is 81 years old and presents after her third fall in six months. She has urge incontinence, insomnia, depression, and osteoarthritis. Medications: oxybutynin 10 mg three times daily, amitriptyline 50 mg at bedtime, diphenhydramine 25 mg at bedtime as needed, and ibuprofen 400 mg three times daily. Her orthostatic vitals show a drop from 128/76 to 102/60 mmHg on standing. She reports dry mouth, constipation, and blurred vision. Her family is worried about her memory, which has worsened over the past year. She lives in an assisted living facility and wants to remain there.
1. Quantify her anticholinergic burden conceptually and identify which medications contribute most. What is your deprescribing sequence?
Read the worked answer
Several of her drugs are strongly anticholinergic: oxybutynin (high), amitriptyline (high), and diphenhydramine (high). Ibuprofen is not anticholinergic but contributes to GI bleeding and renal risk. Using a tool such as the Anticholinergic Cognitive Burden scale, she would score high, and high burden is associated with falls, delirium, and cognitive decline. Her dry mouth, constipation, blurred vision, and memory worsening are consistent with central and peripheral anticholinergic effects. Deprescribe one at a time, starting with the drug that has the least benefit and highest risk: stop diphenhydramine first (no indication for chronic insomnia in older adults; use sleep hygiene and consider melatonin or CBT-I). Next, taper amitriptyline, which is also contributing to orthostasis; if depression needs treatment, switch to sertraline or escitalopram at low dose with monitoring. Then replace oxybutynin with a beta-3 agonist (mirabegron) or behavioral therapy, checking blood pressure because mirabegron can raise it. Reassess falls, cognition, and orthostatic vitals after each change, spaced 2-4 weeks apart.
2. Her orthostatic hypotension and falls need a plan. What non-drug and drug considerations should guide the next steps?
Read the worked answer
First, address the orthostatic drop: measure vitals after lying 5 minutes and standing 1 and 3 minutes. Review contributors: amitriptyline causes alpha-1 blockade and orthostasis; volume depletion from poor intake or diuretics; and deconditioning. Recommend hydration, slow position changes, compression stockings, and avoiding hot showers. Stop amitriptyline as above. If she remains symptomatic after removing offending drugs, consider midodrine or fludrocortisone only with careful monitoring, since fludrocortisone can cause supine hypertension and fluid overload. For the falls, review footwear, vision, home hazards, and vitamin D status. Avoid adding sedatives. Ibuprofen should be stopped or minimized because of GI and renal risk and because it can worsen hypertension; use topical NSAID or acetaminophen for osteoarthritis. Document a falls-prevention plan and communicate it to assisted living staff, who can help with toileting schedules to reduce urgency-related falls.