Tolterodine and Galantamine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Tolterodine
Galantamine
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Decreased efficacy of the cholinesterase inhibitor
Interaction Deep Dive
Concomitant use of a cholinesterase inhibitor, such as galantamine, and an anticholinergic, such as tolterodine, may result in reduced galantamine efficacy. The probable mechanism for this interaction is thought to be cholinergic receptor antagonism by the anticholinergic drug12. In a prospective cohort study, a decline in activity of daily living (ADL), but not cognitive function, was reported in higher functioning nursing home patients (with little to no dependence) 1. Case reports describe delirium in 3 geriatric patients following concomitant use of a cholinesterase inhibitor for Alzheimer's disease and tolterodine for urinary incontinence 2. Therefore, a risk/benefit evaluation should be considered before giving a cholinesterase inhibitor concomitantly with an anticholinergic drug.
Why it happens (mechanism)
Cholinergic receptor antagonism by the anticholinergic drug
Literature reports
2 reports — tap to read
a) A decline in activity of daily living (ADL), but not cognitive function, was reported in high functioning nursing home patients (with little to no dependence) following concomitant use of oxybutynin or tolterodine and a cholinesterase inhibitor in a prospective, cohort study (n=3536). Patients were at least 65 yrs of age, had at least 2 consecutive cholinesterase inhibitor prescriptions, and had not received an anticholinergic other than oxybutynin or tolterodine; resulting in 395 patients with concomitant therapy and 3141 cohorts with cholinesterase inhibitor therapy alone. Cholinesterase inhibitors were donepezil (70.5%), rivastigmine (19.9%), galantamine (16.5%). Of the 3536 patients, nearly 11% were concomitantly prescribed oxybutynin (n=164), tolterodine (n=199), or both drugs at different times (n=13). The median duration of dual use was 141 days. The mean MDS-ADL score was 12.2 +/- 8.1 (scale range, 0 to 28) at baseline. Concomitant use of an anticholinergic and a cholinesterase inhibitor resulted in a decrease of 0.53 ADL points/quarter in high functioning patients compared with the use of a cholinesterase inhibitor alone (p=0.02). ADL scores did not change significantly with concomitant use among lower functioning population (ie, moderate, severe, and complete or nearly complete dependence). Cognitive function, measured using MDS cognitive subscale scores, did not significantly increase with concomitant use compared with cholinesterase use alone in patients regardless of baseline cognitive impairment. Neither the rate of ADL nor that of cognitive function was significantly different for immediate- and extended-release formulations 1.
b) Case reports describe delirium in three 82-year-old patients (2 men, 1 women) following concomitant use of a cholinesterase inhibitor for Alzheimer's disease and tolterodine for urinary incontinence. In case 1, the patient, who was ambulatory, had been receiving donepezil 5 mg at bedtime for the past 2 months. Within one week after starting tolterodine (dose not specified), he developed sudden delusional and aggressive behavior. Subsequently, donepezil was stopped and within 48 hours, his behavior normalized. In case 2, the patient was stable on rivastigmine 6 mg 2 times per day and had been in an assisted living facility for 3 years. She was initiated on tolterodine (dose not specified) and within 1 week, she developed agitation, anxiety, panic attacks, confusion, delusions. Two 0.5-mg lorazepam doses were given with no improvement. Tolterodine was withdrawn 2 days after lorazepam was discontinued. Her symptoms resolved within 24 hours of discontinuing tolterodine. In case 3, the patient had been receiving donepezil 10 mg/day for 2 years due to dementia. His medical history also included Parkinson's disease. He was initiated on tolterodine 20 mg 2 times/day. Disorientation and confusion occurred within 2 weeks of tolterodine initiation. He was taken to the emergency department where tolterodine was stopped. The patient's symptoms resolved within 24 hours of tolterodine discontinuation 2.
Common questions
Can I take Tolterodine and Galantamine together?
Decreased efficacy of the cholinesterase inhibitor Always confirm with your pharmacist or prescriber before making any change.
How serious is the Tolterodine and Galantamine interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Tolterodine or Galantamine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (2)
- Sink KM, Thomas J, Xu H, et al: Dual use of bladder anticholinergics and cholinesterase inhibitors: long-term functional and cognitive outcomes. J Am Geriatr Soc 2008; 56(5):847-853. PubMed
- Edwards KR & O'Connor JT: Risk of delirium with concomitant use of tolterodine and acetylcholinesterase inhibitors. J Am Geriatr Soc 2002; 50(6):1165-1166. PubMed
Keep reading about Tolterodine
Keep reading about Galantamine
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