Dicyclomine

What is dicyclomine?

Dicyclomine belongs to a class of drugs called anticholinergics or antispasmodics. It helps alleviate the symptoms of irritable bowel syndrome (IBS) by reducing muscle spasms in the gastrointestinal (GI) tract.

What You Need To Know About Irritable Bowel Syndrome (IBS)

Dicyclomine is obtained by prescription only. While the oral forms are only sold under the drug’s generic name, the injectable form is also available under the brand name Bentyl. 

What is dicyclomine used to treat?

Dicyclomine is approved by the US Food and Drug Administration (FDA) to treat IBS in adults.¹

Some patients use this medication alone, while others use it alongside other drugs as part of a combination therapy, as directed by their healthcare professional.

Dosage forms and strengths

You can take dicyclomine orally as a tablet, capsule, or syrup. In some cases, it’s administered by a qualified professional in a healthcare setting as an intramuscular injection. The forms and their respective strengths are as follows:

Tablets (generic): 20mg

Capsules (generic): 10mg

Syrup (generic): 10mg/5mL

Injection (generic, Bentyl): 20mg/2mL

Your doctor will determine the appropriate dose and form for you. They’ll consider the following factors:

• Your age

• The reason for treatment

• The severity of your condition

• Your medical history and other health conditions

• Other medications you’re taking 

• Your body’s response to treatment

Oral dicyclomine is available as a 20mg tablet, 10mg capsule, and 10mg/5mL syrup. The injectable solution is produced in a single concentration of 10mg/mL (sometimes depicted as 20mg/2mL).²

How do you take dicyclomine?

Your doctor will tell you how to take dicyclomine to maximize the drug’s effectiveness while reducing the risk of unwanted side effects. Follow your doctor’s instructions precisely. If you’re unsure about something, ask your doctor or pharmacist for clarification. 

People taking oral forms of dicyclomine usually take the medication four times daily. Each dose is taken 30–60 minutes before a meal. Doctors generally prescribe a lower dose and increase the amount weekly as needed.³ ⁴

Dicyclomine intramuscular injections are typically reserved for short-term (1–2 days) use in patients who cannot take one of the oral formulations.⁵

Seeing results

Dicyclomine starts working quickly, within 1–2 hours. When taken orally, the drug reaches peak concentrations in the body within 60–90 minutes.⁶

Dicyclomine treats but does not cure IBS. Its effects are short-lived, lasting less than four hours, so you’ll need to continue taking the medication to keep your symptoms under control.⁷

If you’ve been taking dicyclomine as directed for two weeks and haven’t seen adequate improvements in your symptoms, speak with your doctor about suitable alternatives.⁸

Who should not take dicyclomine?

Dicyclomine is not approved for use by patients under 18 years as its safety has not been established in this age group. The drug is contraindicated, even in small doses, for children younger than six months old and for nursing mothers. There have been cases of severe respiratory symptoms, neurologic events, muscle hypotonia, coma, and death in infants after the administration of the medication.⁹

The drug is also contraindicated for people with the following medical conditions:¹⁰

• Glaucoma

• Myasthenia gravis

• Obstructive disease of the GI tract

• Obstructive uropathy

• Severe ulcerative colitis

• Reflux esophagitis

• Unstable acute hemorrhage 

Additionally, older adults and people with the following medical conditions may require extra caution and monitoring while taking dicyclomine:¹¹

• Heart conditions, including congestive heart failure and coronary heart disease

• High blood pressure

• Enlarged prostate

• Liver or kidney disease

• Non-severe ulcerative colitis

• Fever

• Autonomic neuropathy

• Salmonella dysentery

• Partial intestinal obstruction

Potential side effects of dicyclomine

Some people experience unwanted side effects while taking dicyclomine. Most side effects are mild and resolve without intervention, while others are severe and require treatment or urgent medical attention.¹²

Common side effects

• Dizziness

• Headache

• Dry mouth

• Blurred or double vision

• Drowsiness

• Weakness

• Stomach pain

• Nausea, vomiting

• Gas, bloating

• Constipation

• Poor appetite 

• Tingling

• Difficulty urinating

• Difficulty falling or staying asleep

• Anxiety, excitement, inappropriate mood

Severe side effects

• Confusion

• Forgetfulness

• Hallucinations

• Excessive tiredness

• Muscle weakness

• Unsteadiness

• Fast or pounding heartbeat 

• Fainting

• Coma

• Allergic symptoms, including hives, rash, or difficulty breathing or swallowing 

• Paralytic ileus (temporary paralysis of the intestines)¹³

• Heat stroke¹⁴

If you experience any severe adverse effects while taking dicyclomine, seek urgent medical care. If you experience persistent side effects, regardless of the severity, speak with your doctor.

Overdose

Overdosing on dicyclomine may cause severe adverse effects. Toxic levels of dicyclomine may result in any of the following:¹⁵

• Dilated (large) pupils

• Muscle weakness or paralysis

• Seizures

• Blurred vision

• Headache

• Nausea, vomiting

• Hot, dry skin

• Dizziness

• Dry mouth

• Difficulty swallowing

If you suspect you may have taken too much dicyclomine, call the National Poison Control Center helpline or 911, depending on the severity of your symptoms. 

Allergy information

If you develop allergic symptoms while taking dicyclomine, stop taking the medication and seek immediate medical care. Symptoms of a drug allergy may include:

• Hives, skin itching, rash

• Swelling of the face, lips, tongue, or throat

• Difficulty breathing, wheezing

• Rapid heart rate

• Vomiting

• Loss of consciousness

Long-term use of dicyclomine

Dicyclomine can be used as needed. However, it may become less effective if taken frequently and habitually.¹⁶

Dicyclomine and pregnancy

The US FDA designated dicyclomine as a pregnancy category B drug. While animal studies did not demonstrate harm, there are no adequate, well-controlled studies investigating the effects of the drug on pregnant women taking the recommended daily dose.¹⁷

Your doctor will weigh the potential risks against the drug’s benefits to determine if it’s right for you.

Dicyclomine and breastfeeding

Dicyclomine is excreted in breast milk, and the drug’s safety has not been established in infants under six months of age. Therefore, the drug is contraindicated for use during lactation.¹⁸

Missed doses

If you miss a dose of dicyclomine, take it as soon as you remember. However, if it's nearly time for your next scheduled dose, skip the missed one and take the next dose as usual. Don’t double your dose to make up for a missed one, as doing so may result in an overdose.

Drug interactions

Taking more than one medication may change the way one or both medicines work within the body.¹⁹

For example:

• Dicyclomine can lower or hinder the performance of glaucoma drugs.

• Antacids may lower dicyclomine absorption in the body.

• Dicyclomine may affect the absorption of metoclopramide, ketoconazole, and itraconazole.

Other drugs known to interact with dicyclomine include the following:

• Amantadine

• Sucralfate (Carafate)

• Eluxadoline (Viberzi)

• Trihexyphenidyl

• Digoxin (Lanoxin)

• Dextroamphetamine (Adderall)

• Yohimbe (supplement)

• Phenylephrine (NeoSynephrine, Sudafed PE)

• Loperamide (Imodium)

• Nitroglycerin (Nitrostat) and other nitrates or nitrites

• Vibegron (Gemtesa)

• Antipsychotics such as clozapine (Clozaril) and cariprazine (Vraylar)

• Antidepressants, including tricyclics (clomipramine) like amitriptyline and monoamine oxidase inhibitors (MAOIs) like isocarboxazid (Marplan)

• Antihistamines like pheniramine (Naphcon A, Theraflu, Robitussin)

• Benzodiazepines (Xanax, Klonopin)

• Belladonna alkaloids like ipratropium (Atrovent) and hyoscyamine (Levsin)

• Synthetic cannabinoids, such as dronabinol (Marinol)

• Narcotic pain medications like oxycodone, morphine, and tramadol (ConZip, Qdolo)

• Phenothiazines, including prochlorperazine and olanzapine (Zyprexa)

• Class 1 antiarrhythmic drugs, such as quinidine and disopyramide (Norpace)

• Other anticholinergic drugs, including atropine and glycopyrrolate (Dartisla ODT)

Can I drink alcohol while taking dicyclomine?

Drowsiness is a known side effect of dicyclomine. Because alcohol can make drowsiness worse, you should ask your doctor if it’s safe to drink alcohol while taking the drug.

What to discuss with your doctor before starting dicyclomine

It is important to give your healthcare professional a complete picture of your medical history before starting dicyclomine. At your appointment, you should discuss the following topics:

• Any drug allergies or previous allergic reactions

• Your medical conditions and history, particularly if you have myasthenia gravis, glaucoma, GI conditions, kidney or liver disease, hyperthyroidism, high blood pressure, abnormal heart rhythms, heart disease or heart failure, or prostate conditions

• Any medications (prescribed or over the counter), supplements, herbs, and vitamins you are currently taking or take occasionally

• Alcohol and drug use

• Your family health history

• Current or planned pregnancy or breastfeeding 

• If you work in a high-temperature environment

Stopping dicyclomine

Most people take this medicine intermittently and have no issues upon discontinuing it, except for a return of symptoms. In rare cases, withdrawal symptoms may occur — specifically in long-time users. These symptoms may include dizziness, sweating, and nausea. Accordingly, your doctor may taper your dose if you are planning to stop this medication after frequent usage. 

Drug approval history

• 1950: The US FDA approved dicyclomine²⁰

Tips for taking dicyclomine

The following tips can help you take dicyclomine safely:

• Dicyclomine should be taken at least 30 minutes before a meal. 

• The tablets can be crushed or cut for easier administration.

• Measure the liquid form dosage using a labeled syringe or specified medication measuring device.

• Injectable dicyclomine is for intramuscular administration only, not for oral or intravenous use. Never use injectable dicyclomine for more than two days.

• Be cautious when taking dicyclomine in hot environments, as it can contribute to developing exhaustion heat prostration. Use it with caution if you have a fever. If symptoms like flushing, extreme fatigue, confusion, and agitation develop, discontinue the medication immediately and seek medical assistance.

• Do not operate heavy machinery or perform duties requiring high mental awareness when taking dicyclomine, as the drug can impair cognitive ability.

Frequently asked questions

Is dicyclomine a painkiller?

No, dicyclomine is not a painkiller. However, it may help alleviate pain associated with irritable bowel syndrome through its influence on the muscles in the gastrointestinal tract.

Can I drive while taking dicyclomine?

Dicyclomine can cause drowsiness and blurred or double vision. You should refrain from driving until you know how dicyclomine affects you.²¹