Anticholinergic and Antispasmodic Drugs

Anticholinergic and antispasmodic drugs include a broad class of medications that are used to treat various medical conditions that involve the contraction and relaxation of muscles. Examples of these conditions include overactive bladder, muscle spasms, breathing problems, diarrhea, gastrointestinal cramps, movement disorders, and others. Anticholinergics work by blocking the action of acetylcholine in the brain and at nerves. Neurotransmitters are chemicals made and released by nerves that travel to nearby nerves or, in the case of acetylcholine, nearby muscles and glands where they attach to receptors on the surface of the nerve, muscle, or glandular cells. The attachment of the neurotransmitter can stimulate or inhibit the activity of the receptor-containing cells. Anticholinergic drugs affect the function of many organs by preventing acetylcholine from binding to its receptors.

Anticholinergic drugs decrease the activity of muscles in the gut and reduce the production of sweat, saliva, digestive juices, urine, and tears. Additionally, anticholinergic drugs help to balance the production of dopamine, another neurotransmitter that plays an important role in maintaining mood, movement, memory, attention, problem-solving, motivation, and pleasure.

In addition to drugs that are primarily anticholinergic, there are drugs used for purposes other than nerve, muscle, or glandular problems which have some anticholinergic effects that are considered side effects, for example, antipsychotic and antidepressant drugs

1. Overactive bladder
2. Movement problems in Parkinson's disease
3. Diarrhea
4. Motion sickness
5. Nausea and/or vomiting
6. Muscle spasms
7. Chronic obstructive pulmonary disease (COPD)
8. Asthma

A variety of medications with anticholinergic properties are available for the treatment of various medical conditions.

• Parkinson's medications
• diphenhydramine (Benadryl)
• trihexyphenidyl (Artane -- discontinued brand)
• benztropine mesylate (Cogentin)
• biperiden (Akineton) (This drug is no longer available in the U.S.)
• antipsychotics
• clomipramine (Anafranil)
• chlorpromazine (Thorazine -- discontinued brand)
• clozapine (Clozaril, Fazaclo ODT, Versacloz)
• fluphenazine (Prolixin -- discontinued brand)
• loxapine (Adasuve; Loxitane -- discontinued brand)
• olanzapine (Zyprexa, Symbyax)
• perphenazine (Trilafon -- discontinued brand)
• pimozide (Orap)
• quetiapine (Seroquel)
• thioridazine (Mellaril -- discontinued brand)
• thiothixene (Navane -- discontinued brand)
• trifluoperazine (Stelazine -- discontinued brand)

• oxybutynin (Ditropan XL; Ditropan -- discontinued brand)
• darifenacin (Enablex)
• solifenacin (Vesicare)
• fesoterodine (Toviaz)
• tolterodine (Detrol)
• trospium (Sanctura)

• belladonna
• chloridiazepoxide (Librium)
• dicyclomine (Bentyl)
• hyoscyamine (Levsin) (This drug is no longer available in the U.S.)

• amitriptyline (Elavil, Endep)
• amoxapine (Asendin)
• clomipramine (Anafranil)
• desipramine (Norpramin)
• doxepin (Silenor)
• imipramine (Tofranil)
• nortriptyline (Pamelor)
• protriptyline (Vivactil)
• trimipramine (Surmontil)

• cyclobenzaprine (Amrix; Flexeril-Discontinued brand)
• dantrolene (Dantrium, Revonto, Ryanodex)
• carisoprodol (Soma)
• methocarbamol (Robaxin)
• orphenadrine (Norflex-Discontinued brand)
• tizanidine (Zanaflex)

• meclizine (Antivert-Discontinued brand
• scopolamine (Transderm Scope)

• atropine
• belladonna
• dicyclomine (Bentyl)
• hyoscyamine (Levsin) (This drug is no longer available in the US)
• loperamide (Imodium)
• promethazine (Phenergan)

• ipratropium (Atrovent, Combivent, Duoneb)
• tiotropium (Spiriva)
• aclidinium (Tudorza Pressair)
• umeclidinium and vilanterol (Anoro Ellipta)

• Blurred vision
• Dry mouth
• Dry eyes
• Decreased urine production
• Decreased sweat production
• Constipation
• Memory impairment
• Delirium
• Confusion

When possible, the use of anticholinergics should be avoided in the elderly because anticholinergic side effects are particularly common and problematic in older individuals.

Patients with the following medical conditions should not use medications with anticholinergic properties since the use of anticholinergic medications can worsen their conditions:

• Benign prostate hyperplasia (enlarged prostate)
• Glaucoma
• Urinary bladder neck obstruction
• Myasthenia gravis
• Alzheimer's disease

The use of multiple drugs with anticholinergic properties may be problematic because of their cumulative anticholinergic side effects. Examples of medications with anticholinergic properties that should not be combined include:

• Antipsychotics
• Certain antidepressants
• Histamine 1-receptor blockers (H1RA)
• Antispasmodics
• Anti-diarrheal medications
• Parkinson's medications
• Overactive bladder (OAB) medications
• Motion sickness medications
• Certain antiemetics

Patients are advised to consult with their doctor or pharmacist for more information regarding potential drug interactions.

Pregnancy

Most of the available anticholinergic medications have not been adequately studied in pregnant women. Patients who are pregnant or plan on becoming pregnant should consult with their doctor before starting a regimen that contains anticholinergic medications.

Breastfeeding

Many drugs can enter human milk and cause unwanted side effects in the nursing baby. Therefore, all medications should be used cautiously in nursing mothers. The prescribing information for each drug should be consulted for recommendations about use while breastfeeding.