What Category is dicyclomine in? Understanding its Anticholinergic and Antispasmodic Actions

October 10, 2025 •

3 min read

According to the U.S. National Library of Medicine, dicyclomine belongs to a class of medications called anticholinergics. It is also known as an antispasmodic due to its primary function of relaxing muscles in the gastrointestinal tract to treat symptoms of irritable bowel syndrome (IBS). Understanding what category is dicyclomine in helps clarify its mechanism of action and therapeutic uses.

Quick Summary

Dicyclomine is a medication classified as both an anticholinergic and an antispasmodic. It relieves gastrointestinal spasms and cramping associated with irritable bowel syndrome by blocking acetylcholine and acting directly on smooth muscle. Due to its mechanism, it has specific side effects and contraindications.

Key Points

Drug Class: Dicyclomine is an anticholinergic and an antispasmodic medication, primarily used for gastrointestinal issues.
Mechanism: It works by blocking the neurotransmitter acetylcholine and directly relaxing the smooth muscles of the digestive tract.
Primary Use: It is prescribed to alleviate cramping and spasms associated with Irritable Bowel Syndrome (IBS).
Common Side Effects: Expected side effects include dry mouth, blurred vision, dizziness, drowsiness, and constipation.
Contraindications: The drug should not be used in patients with glaucoma, myasthenia gravis, or obstructive gastrointestinal/urinary conditions.
Important Warnings: Dicyclomine can increase the risk of heatstroke by decreasing sweating, so caution is needed in high temperatures.
Patient Precautions: Patients should avoid activities requiring alertness, as the drug can cause drowsiness and blurred vision.

What Category is Dicyclomine in?

Dicyclomine (Bentyl®) is classified as an anticholinergic and antispasmodic. These terms describe how the drug works and its therapeutic effect.

Anticholinergic: Dicyclomine blocks the action of acetylcholine, a neurotransmitter that signals muscles to contract. It specifically targets muscarinic acetylcholine receptors in the GI tract.
Antispasmodic: By relaxing the smooth muscles of the gastrointestinal tract, dicyclomine relieves spasms and cramping associated with conditions like Irritable Bowel Syndrome (IBS).

The Dual-Action Mechanism

Dicyclomine's ability to relieve spasms comes from a dual mechanism. It blocks acetylcholine receptors and also has a direct effect on smooth muscle, leading to muscle relaxation and slowed gut movement.

Therapeutic Uses: Managing Irritable Bowel Syndrome

Dicyclomine is primarily used to treat functional bowel disorders, especially IBS. It helps relieve symptoms such as:

Stomach and intestinal cramping
Abdominal pain
Bloating

It is important to note that dicyclomine manages IBS symptoms and is often used for short-term relief of flare-ups.

Potential Side Effects of Dicyclomine

Since dicyclomine affects acetylcholine receptors throughout the body, various side effects can occur. Common side effects include:

Dry mouth
Blurred vision
Drowsiness or dizziness
Nausea and constipation
Feeling nervous or weak

Less common but more serious side effects requiring immediate medical attention include:

Confusion or hallucinations
Fast or irregular heartbeat
Difficulty urinating
Decreased sweating, which can increase the risk of heatstroke

Important Considerations and Contraindications

Dicyclomine is not suitable for everyone. It should not be used in:

Infants under 6 months: Due to the risk of serious adverse events.
Nursing Mothers: It can be excreted in breast milk and harm the infant.
Individuals with Glaucoma: It can increase pressure in the eye.
Individuals with Myasthenia Gravis: It can worsen muscle weakness.
Individuals with Obstructive Diseases: Such as blockages in the GI or urinary tract, as it can worsen symptoms.
Individuals with Severe Ulcerative Colitis: It increases the risk of toxic megacolon.

Use with caution in elderly patients and those with heart, liver, or kidney problems.

Dicyclomine vs. Hyoscyamine: A Comparison

Dicyclomine and hyoscyamine are both anticholinergic antispasmodics for IBS, but they have differences.


Feature	Dicyclomine	Hyoscyamine
Onset of Action	Takes longer to work (40-60 minutes).	Works faster (30-60 minutes), good for acute relief.
Formulations	Capsules, tablets, syrup, and injection.	Immediate and extended-release forms, including sublingual tablets.
Typical Use Case	More for consistent symptom control.	Better for quick relief of severe pain episodes.
Side Effects	May have fewer systemic side effects, but still causes anticholinergic effects.	Can cause more widespread anticholinergic effects.

The choice depends on individual symptoms and needs, and should be discussed with a healthcare provider.

Conclusion: Dicyclomine's Role in IBS Management

Dicyclomine, as an anticholinergic and antispasmodic, helps manage the painful spasms and cramping of IBS by blocking acetylcholine and relaxing smooth muscle. While effective for specific patients, its systemic effects mean side effects are possible, and it's not suitable for everyone. Proper medical supervision and patient education on dosage, precautions, and symptom monitoring are essential for safe and effective use. More detailed information can be found on MedlinePlus from the U.S. National Library of Medicine.

Frequently Asked Questions

Yes, dicyclomine is an anticholinergic medication. It works by blocking the action of acetylcholine, a chemical messenger, which leads to the relaxation of smooth muscles in the gastrointestinal tract.

The primary use of dicyclomine is to treat the symptoms of Irritable Bowel Syndrome (IBS), such as intestinal cramping, abdominal pain, and spasms.

The most common side effects include dry mouth, blurred vision, dizziness, drowsiness, nausea, and constipation. Many of these are related to its anticholinergic properties.

Dicyclomine has a dual mechanism of action. It blocks acetylcholine-receptor sites (anticholinergic effect) and has a direct relaxant effect on smooth muscle (musculotropic effect), which together relieve gastrointestinal spasms.

No, dicyclomine is not a narcotic and is not considered a controlled substance. It is a prescription medication used to manage IBS symptoms.

Dicyclomine is contraindicated in infants under 6 months, nursing mothers, and individuals with conditions such as glaucoma, myasthenia gravis, and certain obstructive gastrointestinal diseases.

Yes, dicyclomine can cause central nervous system effects like confusion, disorientation, and hallucinations, particularly in older adults who may be more sensitive to its side effects.