Anticholinergics are medications that are administered to lessen the nervous system's stimulation of smooth muscle tissue. An anticholinergic works by inhibiting the action of acetylcholine, the neurotransmitter responsible for signaling nerve activity. Forms of the drug have proven to be effective in treating a wide variety of conditions, including gastrointestinal problems to asthma. Doctors are careful when prescribing these medications to minimize the risk of adverse drug reactions and negative side effects, such as dry mouth, headaches or nausea—or more severely, respiratory issues or mental confusion.
Involuntary smooth muscle contractions in the lungs, gastrointestinal tract, urinary tract, and elsewhere in the body are controlled by the parasympathetic nervous system (PSNS). Acetylcholine produced by the brain normally regulates PSNS activity, but over-stimulation can occur if there is too much of the neurotransmitter or if it is not absorbed correctly. When an anticholinergic is administered, it travels to nerves in the PSNS and blocks the receptor sites for acetylcholine, thereby dulling the contraction response.
A patient may be prescribed this medication for several reasons, but the drug is most commonly given to alleviate gastrointestinal and urinary problems. People who suffer from frequent stomach cramps, peptic ulcers, irritable bowel syndrome, and ulcerative colitis can usually find relief from symptoms by taking anticholinergics. The drug can also help relieve lung disorders by relaxing muscle tissue and preventing airways from becoming constricted. In addition, an anticholinergic may be given before or during a surgical procedure to desensitize the PSNS.
Certain side effects are common with anticholinergic use, though they are usually mild and temporary. Since smooth muscle is involved with mucus and fluid production, a patient taking this medication may experience dry mouth, constipation, and difficulty swallowing. Some people have headaches, nausea, joint pain, and chest tightness. Less commonly, the drug can cause mental confusion and severe breathing problems. Allergic reactions are rare, and typically cause airway constriction, hives, and a rapid heart rate.
A doctor can limit the chance of experiencing side effects by thoroughly reviewing a patient's medical history and current medication use. Dosage amounts depend on many factors, including a person's age and specific medical condition. Most are taken in oral doses once or twice daily, though dissolving powders, suppositories, and intravenous solutions are also available.
It is very important to follow a doctor's directions exactly when taking an anticholinergic or any other type of prescription medication. An overdose could cause severe health complications, including cardiac arrest, lung failure, and brain damage. Any unusual minor side effects should be reported to the prescribing doctor, while allergic reactions and breathing difficulties typically require a trip to the emergency room. Most people who are given these medications experience significant relief from their symptoms without negative consequences.