What are Anticholinergics?
Anticholinergics are a class of drugs that block the action
of the neurotransmitter acetylcholine in the brain. They are used to treat
diseases like asthma, incontinence, gastrointestinal cramps, and muscular
spasms. They are also prescribed for depression and sleep disorders. The drugs
help to block involuntary movements of the muscles associated with these
diseases. They also balance the production of dopamine and acetylcholine in the
body. Anticholinergics can also be used to treat certain types of toxic
poisoning, and are sometimes used as an aid to anesthesia.
Most anticholinergics are only available with a doctor’s prescription.
Some examples include:
- Trihexyphenidyl (Artane)
- Benztropine mesylate (Cogentin)
- 2,5 antihistamines (orphenadrine)
- Flavoxate (Urispas)
- Oxybutynin (Ditropan, Oxytrol)
- Hyoscyamine (Levsinex)
- Tolterodine (Detrol)
- Belladonna alkaloids
- Fesoterodine (Toviaz)
- Solifenacin (VESIcare)
- Darifenacin (Enablex)
- Propantheline (Pro-Banthine) (UCSF)
There are many other types available. A doctor will select
the best medication for your condition.
Note that a few over-the-counter drugs have anticholinergic effects, including:
- Diphenhydramine (Benadryl)
- Clemastine (Tavist)
What are Anticholinergics Used to Treat?
Anticholinergics are used to treat a variety of conditions.
- gastrointestinal disorders, such as diarrhea,
overactive bladder, and incontinence
- chronic obstructive pulmonary disease (COPD)
- dizziness and motion sickness
- poisoning caused by toxins such as
organophosphates or muscarine
- hypertension (high blood pressure)
- symptoms of Parkinson’s disease
The drugs can also be used as muscle relaxants during
surgery to assist with anesthesia. They help a patient to relax and decrease
saliva secretions (Mayo Clinic).
How Do Anticholinergics Work?
Anticholinergics are derived from plants of the deadly nightshade
family called Solanaceae. Burning of the roots, stems, and seeds of these
plants releases substances called alkaloids. One of these alkaloids is the antimuscarinic
agent called atropine. Inhalation of smoke from these plants has been used for
hundreds of years to treat obstructive airways disease (Scullion, 2007).
Anticholinergics work by inhibiting parasympathetic nerve
impulses. They do this by blocking the binding of acetylcholine to its receptor
present in nerve cells. The parasympathetic nerve system is one of the two main
parts of the automatic nervous system
(ANS). It manages activities that occur when the body is at rest. It is
often called the “rest and digest system.” The nerves in the parasympathetic
system are responsible for involuntary movement of muscles in the
gastrointestinal tract, lungs, urinary tract, and other parts of the body.
Who Should Not Take Anticholinergics?
Anticholinergics are not
usually prescribed to older people. The
elderly are more sensitive to their effects compared to younger adults (Mayo Clinic). The
medicines are known to cause confusion, memory loss, worsening of mental
function, and other cognitive effects in the elderly.
drugs should also not be used in people with the following conditions:
(high blood pressure)
of the urinary tract
heart rate (tachycardia)
syndrome (Mayo Clinic)
should also not be used by people with an allergy to anticholinergic agents.
Tell your doctor if you have any of the above conditions or have a history of
allergies to medications in this drug class.
medication may cause a decrease in sweating, and your body temperature may
increase as a result. You should use extra caution to not become overheated
during exercise, hot baths, or in a hot weather. The decrease in sweating can
result in heat stroke.
What are the Side Effects of Anticholinergics?
Side effects depend on dose. You may or may not experience
any side effects. Check with your health care professional if side effects
continue or become bothersome or severe. Side effects of anticholinergics may
- dry mouth
- blurred vision
- memory impairment
- difficulty urinating
- decreased sweating
- decreased saliva
Signs of an overdose include:
- severe drowsiness
- severe hallucinations
- trouble breathing
- clumsiness and slurred speech
- fast heartbeat
- flushing and warmth of the skin
An overdose of certain anticholinergics or taking them with
alcohol can result in unconsciousness or even death. Seek emergency help
immediately if you or someone you know may have taken an overdose.