What You Need to Know About Bentyl (Dicyclomine)

Prescribing, Dosing, Side Effects, and Use During Pregnancy and Nursing

Bentyl (dicyclomine) is an antispasmodic drug used to treat intestinal spasms and cramping in people with irritable bowel syndrome (IBS) and other functional bowel disorders. Dicyclomine can be used both in adults and children and is available as a tablet, capsule, syrup, or injection. (Only the injection is still used under the trade name Bentyl.)

Bentyl can cause side effects and interact with certain drugs, but the benefits may outweigh the risks when faced with severe IBS symptoms.

This article describes the uses, dosage, risks, side effects, and interactions associated with taking Bentyl.

Young woman taking a pill
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Uses of Bentyl

Bentyl belongs to a class of drugs known as anticholinergics that block the action of a chemical known as acetylcholine. Acetylcholine is used by the body to contract smooth (involuntary) muscles in the airways, bladder, blood vessels, gastrointestinal (digestive) tract, and others of the body.

By doing so, drugs like Bentyl can relieve spasms in the gut and intestines.

Bentyl is approved for use by the U.S. Food and Drug Administration (FDA) in treating IBS and other functional bowel disorders. These are conditions of unknown origin affecting the middle and lower intestines that cause a cascade of chronic (persistent) symptoms, including abdominal pain, bloating, indigestion, stool irregularity, diarrhea, and constipation.

Irritable bowel syndrome is the most common type of functional bowel disorder. 

Before Taking Bentyl

Tell your healthcare provider about all medications, supplements, and vitamins you take before starting Bentyl. While some drugs pose minimal risks, others can cause severe interactions and/or side effects when used together.

Precautions and Contraindications

Because anticholinergic drugs affect smooth muscles throughout the body, they can affect the normal contraction of other organs and may be inappropriate for people with certain health conditions.

Tell your healthcare provider if you have any of the following:

Dicyclomine is a pregnancy category B drug, meaning that no harm was reported in animal studies but studies in humans are lacking. Dicyclomine should only be used during pregnancy if the benefits outweigh the risks. Notify your healthcare provider if you become pregnant while taking dicyclomine.

Bentyl should not be taken while breastfeeding as the drug can be passed into breast milk.

Warning in Infants

Bentyl should never be used in children under 6 months of age as it can severely slow breathing and lead to acute respiratory distress.

Bentyl Dosage

Bentyl can be taken by mouth as a tablet, capsule, or syrup. It is also formulated as an intramuscular injection (meaning a shot into a large muscle) for temporary use in those who can't take oral medication.

The Bentyl dose is measured in milligrams (mg). A typical starting dose of the oral forms is 80 mg/day, divided equally into four doses. If that is tolerated but not effective, the dosage may be increased to 160 mg/day.

The injection is given in doses of 10 mg or 20 mg four times per day.

Warning About Antacids

Bentyl should not be taken at the same time as an antacid, such as Tums, Rolaids, Gaviscon, Maalox, or Mylanta. Doing so can reduce the absorption and effectiveness of Bentyl. Separate the doses by at least a couple of hours.

If a dose is missed, take it as soon as you remember. If the next dose is soon, skip the missed dose and continue as normal. Never double up doses as it can increase the risk or severity of side effects.

Bentyl Side Effects

As with all drugs, Bentyl can cause side effects ranging from mild to severe. Some people have no side effects at all.

Common side effects of Bentyl include:

  • Dry mouth
  • Dizziness or light-headedness
  • Blurred vision
  • Nausea
  • Drowsiness
  • Weakness
  • Nervousness or agitation
  • Stuffy nose
  • Headache
  • Abdominal bloating
  • Constipation
  • Insomnia

Call your health provider immediately if the side effects are severe or you experience any of the following uncommon side effects:

  • Rash
  • Hot, dry skin
  • Difficulty breathing
  • Difficulty swallowing
  • Vomiting
  • Rapid or irregular heartbeats
  • Mood changes
  • Delirium
  • Hallucinations
  • Fainting
  • Unsteadiness
  • Weakness

Warnings and Interactions

Bentyl can interact with other drugs with similar anticholinergic effects. There are also certain drugs that can either lower or increase the concentration of Bentyl in the blood.

Tell your healthcare provider if you take any of the following before starting Bentyl:

People taking Bentyl should also avoid alcohol as it can increase the drug’s sedative effects.

Frequently Asked Questions

  • Does Bentyl lower blood pressure?

    Yes, it can. Because Bentyl (dicyclomine) works by relaxing smooth muscles, like those in blood vessels, it can cause blood pressure to drop, causing dizziness and lightheadedness. This is why you should never drive or use heavy machinery while taking Bentyl. With that said, Bentyl is not used to treat high blood pressure.

  • Does dicyclomine help with anxiety?

    Bentyl (dicyclomine) does not help with anxiety. In fact, nervousness and agitation are two common side effects of a drug commonly used to treat irritable bowel syndrome (IBS).

  • Is Bentyl addictive?

    It is very rare for people to become addicted to Bentyl, but some studies have shown that people can grow physically dependent on it. This is usually due to the overuse of Bentyl, during which the body becomes so accustomed to the drug that it reacts badly if the drug is suddenly stopped.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Library of Medicine: DailyMed. Bentyl: dicyclomine hydrochloride injection, solution [drug label].

  2. Canadian Agency for Drugs and Technologies in Health (CADTH). Summary of evidence. In: Dicyclomine for Gastrointestinal Conditions: A Review of the Clinical Effectiveness, Safety, and Guidelines [Internet]. Ottawa ON: CADTH; Dec 2015.

  3. Hauser W, Layer P, Henningsen P, Kruis W. Functional bowel disorders in adults. Dtsch Arztebl Int. 2012;109(5):83–94. doi:10.3238/arztebl.2012.0083

  4. National Library of Medicine: DailyMed. Dicyclomine: dicyclomine hydrochloride tablet [drug label].

  5. National Library of Medicine: DailyMed. Dicyclomine.

  6. Das S, Mondal S, Datta A, Bandyopadhyay S. A rare case of dicyclomine abuseJ Young Pharm. 2013;5(3):106-107. doi:10.1016/j.jyp.2013.08.004

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.