Anticholinergic Drugs to Avoid in the Elderly
Medically reviewed on Feb 10, 2016 by L. Anderson, PharmD.
Anticholinergic Drugs and Acetylcholine
Anticholinergic drugs block (antagonize) the action of the neurotransmitter acetylcholine. A neurotransmitter is a chemical released by nerve cells to send signals to other cells. Acetylcholine is involved in transmitting messages that affect muscle contractions in the body and learning and memory in the brain. Drugs with anticholinergic properties have been used in medicine for many decades in the treatment of such diverse conditions as:
- Overactive bladder and urinary incontinence
- Chronic obstructive pulmonary disease (COPD)
- Surgery and anesthesia for muscle relaxation
- Motion sickness
- Toxicity of certain poisonings
- Parkinson’s disease symptoms
- Psychiatric disorders
However, drugs with anticholinergic properties can be problematic, especially for the elderly.
Medications To Avoid in Elderly
Why should many anticholinergic drugs be avoided in the elderly? Chemical properties of these drugs can cause a wide array of more pronounced reactions in the elderly.
The central nervous system is very sensitive to anticholinergic side effects due to the substantial decrease in cholinergic neurons or receptors in the brain of older individuals. In addition, the lower ability of the liver and kidney to break down and excrete medications, and the increase in the blood–brain barrier permeability which allows drugs to cross more easily into the brain, are major factors contributing to anticholinergic side effects in older adults. Most commonly, anticholinergics can cause the following side effects, which may be more pronounced in the elderly:
- Drowsiness or sedation
- Blurred vision
- Urinary retention
- Confusion or delirium
- Dry mouth
- Reduced sweating and elevated body temperature
- Falls and risk for fracture
Anticholinergic drugs fall into many different classes of drugs, so it’s hard for patients to identify or remember these specific drugs. For example, some antihistamines, antidepressants, or even muscle relaxants have anticholinergic properties. Patients with delirium, dementia, constipation, and benign prostatic hypertrophy (BPH) are particularly at risk of anticholinergic adverse drug events. Refer to the list below for a list of anticholinergic drugs to avoid in older patients.
Anticholinergic drugs should be avoided in patients with dementia, cognitive impairment, or delirium. A study from Group Health in Seattle and published in JAMA Internal Medicine in 2015 noted that higher cumulative anticholinergic medication use was associated with an increased risk for dementia. Data were evaluated from a prospective, population-based cohort study using data from the Adult Changes in Thought Study. Over 3,400 participants aged 65 and older with no dementia were enrolled at study entry between 1994 and 2003. It was found the most common anticholinergic drug classes used by the elderly in the study were tricyclic antidepressants, first generation antihistamines and overactive bladder antimuscarinics. Overall, a higher cumulative use of anticholinergic medications (3 years or more) across all subclasses was linked with a 54% higher risk for developing dementia than taking the same dose for three months or less. Results also suggested that the risk for dementia with anticholinergics remain even after drug discontinuation.
Anticholinergic drugs should not be used in conditions such as:
- Benign prostatic hypertrophy (BPH)
- Angle closure glaucoma
- Myasthenia gravis
- Alzheimer’s disease
- Bowel blockage
- Urinary tract blockage or urinary hesitancy
In the acute hospital setting, anticholinergic drugs should not be started in the elderly unless clearly needed, and use of any anticholinergic drug given as an outpatient should be suspended, unless clearly needed with no other more appropriate alternatives. In addition, opioids for pain and anticholinergics should especially be avoided concomitantly in the acute care setting due to greater risk of confusion, sedation, hallucination, opioid-induced constipation or fecal impaction.
Patients and clinicians should avoid abruptly stopping long-term anticholinergic drugs, when possible, to minimize withdrawal symptoms. A slower taper may help to avoid side effects.
Beers Guidelines 2015
Per the Beers Criteria, most recently updated in 2015, it is well established that many drugs with anticholinergic properties should be avoided in the elderly whenever possible. In addition, drug Interactions with anticholinergics are common and pharmacists and physicians should screen for these drug interactions in patients who must use a drug with anticholinergic properties. It is also important to screen for and avoid combined use of two or more drugs that both have anticholinergic effects to minimize the risk for adverse drug effects.
Clinicians can also refer to the Anticholinergic Cognitive Burden (ACB) Scale developed by the Aging Brain Program of the Indiana University Center for Aging Research. On this list, drugs that have an ACB score higher than ‘3’ should be avoided in the elderly.
List of Anticholinergic Drugs to Be Avoided in the Elderly
Note: Many of the below drugs are found in over-the-counter (OTC) products and/or in combination with other medications (prescription or OTC), so always check with your pharmacist if you are concerned about the use of anticholinergic drugs.
- Carbinoxamine (Arbinoxa, Karbinal ER, Palgic)
- Chlorpheniramine (Aller-Chlor, Chlor-Trimeton)
- Clemastine (Tavist Allergy)
- Dexbrompheniramine (Ala-Hist IR)
- Dexchlorpheniramine (Polaramine, Polaramine Repetabs)
- Dimenhydrinate (Dramanine)
- Diphenhydramine* (oral) (Allermax, Benadryl, Nytol, Unisom)
- Doxylamine (Aldex AN, Unisom, Nytol Maximum Strength)
- Hydroxyzine (Vistaril, Atarax)
- Meclizine (Antivert, Bonine, D-Vert, Dramamine Less Drowsy)
- Promethazine (Phenergan)
- Triprolidine (Histex, Zymine, Zymine, Tripohist)
* Use of diphenhydramine in acute allergic reactions may be appropriate
* In general, these agents are not recommended for prevention of extrapyramidal symptoms with antipsychotics. In addition, more-effective agents are available for treatment of Parkinson disease.
Skeletal Muscle Relaxants
- Disopyramide (Norpace, Norpace CR)
- Clomipramine (Anafranil)
- Desipramine (Norpramin)
- Doxepin (Silenor, Sinequan)
- Imipramine (Tofranil, Tofranil-PM)
- Nortriptyline (Pamelor)
- Paroxetine (Brisdelle, Paxil, Paxil CR, Pexeva)
- Protriptyline (Vivactil)
- Trimipramine (Surmontil)
Antimuscarinics (Urinary Incontinence)
- Darifenacin (Enablex)
- Fesoterodine (Toviaz)
- Flavoxate (Urispas)
- Oxybutynin (Ditropan, Ditropan XL)
- Solifenacin (Vesicare)
- Tolterodine (Detrol, Detrol LA)
- Trospium (Sanctura, Sanctura XR)
- Clozapine (Clozaril, FazaClo, Versacloz)
- Loxapine (Loxitane)
- Olanzapine (Zyprexa, Zyprexa Relprevv, Zyprexa Zydis)
*Boxed warnings exist about the use of antipsychotics in the elderly with dementia. Antipsychotics are not approved for use in psychotic conditions related to dementia. Antipsychotics may increase the risk of death in older adults with dementia-related conditions.
- Atropine (excludes ophthalmic [eye] agents)
- Belladonna Alkaloids
- Clidinium-chlordiazepoxide (Librax)
- Dicyclomine (Bentyl)
- Homatropine (excludes ophthalmic [eye] agents) (Tussigon)
- Hyoscyamine (Anaspaz, Levbid, Levsin, NuLev)
- Scopolamine (excludes ophthalmic) (Transderm Scop)
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- American Geriatrics Society 2015 Updated Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. J Am Geriatr Soc 63:2227–2246, 2015. Accessed December 29, 2015 at http://onlinelibrary.wiley.com/doi/10.1111/jgs.13702/full
- Campbell N, Boustani M, Limbil T, et al. The Cognitive Impacts of Anticholinergics: A Clinical Review. Clin Interv Aging. 2009;4: 225–233. Accessed December 30, 2015 at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2697587/
- Gray SL, Anderson ML, Dublin S et al. Cumulative use of strong anticholinergics and incident dementia: A prospective cohort study. JAMA Intern Med 2015;175:401–407.
- Merz B. Common anticholinergic drugs like Benadryl linked to increased dementia risk. Harvard Health Blog. September 10, 2015. Accessed January 11, 2016 at http://www.health.harvard.edu/blog/common-anticholinergic-drugs-like-benadryl-linked-increased-dementia-risk-201501287667
- Anticholinergic Cognitive Burden Scale. 2012 Update. Aging Brain Program of the Indiana University Center for Aging Research. Accessed January 11, 2016 at http://www.agingbraincare.org/uploads/products/ACB_scale_-_legal_size.pdf