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)
Anticholinergics are used to treat a variety of conditions. These include:
- 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).
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.
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.
The drugs should also not be used in people with the following conditions:
- myasthenia gravis
- enlarged prostate
- hypertension (high blood pressure)
- blockage of the urinary tract
- increased heart rate (tachycardia)
- heart failure
- severe dry mouth
- hiatal hernia
- severe constipation
- liver disease
- Down’s syndrome (Mayo Clinic)
They 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.
The 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.
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 include:
- 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.