Diclomine

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Diclomine

Method of action: Analgesic, Antispasmodic

Treatment option:

Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Diclomine

What is Diclomine?

Diclomine is a medication primarily classified as an anticholinergic and antispasmodic agent. It is used to manage symptoms associated with functional bowel disorders, particularly irritable bowel syndrome (IBS). The medication works by targeting the smooth muscles of the gastrointestinal tract, helping to alleviate symptoms such as cramping and abdominal pain.

Mechanism of Action

The gastrointestinal tract relies on coordinated muscle contractions to move contents through the system. In certain conditions, these muscles may undergo spasms or excessive contractions, leading to discomfort. Diclomine functions by blocking the action of acetylcholine, a chemical messenger in the body that signals muscles to contract. By inhibiting these signals at specific receptor sites in the gut, the medication promotes muscle relaxation and reduces the frequency and intensity of intestinal spasms.

Primary Uses

Diclomine is specifically indicated for the treatment of functional disturbances in gastric motility. Its use is focused on providing relief from the physical manifestations of bowel dysfunction, including:

  • Abdominal Cramping: Reducing the severity of muscle spasms in the stomach and intestines.
  • Irritable Bowel Syndrome: Addressing the muscular hyperactivity often associated with this chronic condition.

By focusing on the underlying smooth muscle activity, the medication helps stabilize the movement of the digestive system.

Regulatory References

  1. NCBI Bookshelf LiverTox

What side effects are possible with Diclomine?

Diclomine: Possible Side Effects and Safety Information

As an anticholinergic agent, the documented safety profile of Diclomine is characterized by adverse reactions related to the inhibition of acetylcholine. The most common adverse reactions reported in clinical trials and official regulatory labeling typically involve the Gastrointestinal and Nervous Systems and the Eyes.

Reactions classified as common in official documents include dry mouth, dizziness, and blurred vision. Other documented side effects spanning various System-Organ Classes (SOCs) include somnolence, nervousness, constipation, nausea, urinary hesitancy, urinary retention, and tachycardia.

Serious Adverse Reactions and Safety Constraints

The prescribing information highlights the potential for serious adverse reactions, including anaphylaxis, toxic psychosis, and, particularly in infants, serious respiratory symptoms such as respiratory collapse, apnea, and seizures; deaths have been reported in this age group. Due to this risk, the medicine is contraindicated in infants less than six months old.

Official regulatory documents also list other mandatory restrictions. The drug is contraindicated in patients with pre-existing conditions such as obstructive uropathy, obstructive gastrointestinal disease (like paralytic ileus), severe ulcerative colitis, reflux esophagitis, glaucoma, and myasthenia gravis.

Furthermore, caution is required for the older adult population, who may be more susceptible to central nervous system effects such as confusion and excitement. The label notes that central nervous system symptoms generally resolve within 12 to 24 hours after discontinuing the medicine.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose of Diclomine is characterized by severe clinical manifestations resulting from its anticholinergic properties, requiring immediate professional medical attention.

Documented Clinical Signs

Official regulatory documents list overdose presentations that primarily involve the central nervous system (CNS) and autonomic effects. These include headache, dizziness, vomiting, CNS stimulation, blurred vision, dilated pupils, hot, dry skin, and difficulty in swallowing.

Severe and Life-Threatening Outcomes

The official profile highlights the potential for severe toxicity, specifically seizures, syncope, and coma. A curare-like action leading to neuromuscular blockade and potential paralysis is also documented. For infants less than 6 months of age, the regulatory warnings indicate a heightened risk for serious respiratory symptoms, including respiratory collapse, apnea, and death.

Emergency Action and Management

The development of severe symptoms necessitates that the drug be discontinued and that immediate medical attention be sought. Management procedures described in regulatory texts include methods to reduce absorption, such as gastric lavage and activated charcoal, and the use of sedatives for managing excitement. An appropriate parenteral cholinergic agent is officially specified as a potential antidote, if indicated. It is noted that it is not known if the substance is dialyzable.

Therapeutic Uses of Diclomine

What Diclomine Treats: Main Uses and Benefits

Diclomine is a medication primarily utilized to manage functional bowel disorders. It belongs to a class of drugs known as anticholinergics or antispasmodics. Its main application is in the treatment of symptoms associated with Irritable Bowel Syndrome (IBS), a condition characterized by disruptions in the normal movement and function of the digestive tract.

Primary Indications

The medication is indicated for the following gastrointestinal concerns:

  • Irritable Bowel Syndrome (IBS): Diclomine is used to alleviate the abdominal pain and discomfort that occurs when the muscles in the digestive system contract irregularly.
  • Functional Bowel Disorders: It helps manage conditions where the primary issue is the way the gut functions rather than a structural or biochemical abnormality.

Mechanism of Action

Diclomine works by affecting the smooth muscles of the gastrointestinal tract. It helps to:

  • Reduce Muscle Spasms: It blocks the action of certain natural chemicals in the body that cause muscles in the gut to contract or spasm.
  • Slow Gut Motility: By relaxing these muscles, the medication helps slow down the natural movements of the digestive system, which can be overactive in certain conditions.

Therapeutic Benefits

When integrated into a broader management plan, the benefits of dicyclomine include:

  • Relief of Abdominal Cramping: By preventing excessive muscle contractions, it helps reduce the frequency and severity of painful stomach cramps.
  • Improvement in Digestive Comfort: The relaxation of the intestinal muscles often leads to a reduction in the bloating and general discomfort associated with functional gut disorders.
  • Normalization of Bowel Function: For patients experiencing urgency or cramping due to hypermotility, the medication can help stabilize the pace of the digestive process.

Regulatory References

  1. NIH MedlinePlus Drug Information

Eligibility and Restrictions for Use

Official Population Eligibility for Diclomine

Regulatory documents define specific populations who are contraindicated and must not use Diclomine (dicycloverine). Use is generally approved for adults when no contraindications are present.


Absolute Contraindications

The medicine is prohibited for use in infants less than 6 months of age and is contraindicated in nursing mothers. It is also contraindicated in patients with the following conditions:

  • Glaucoma or Myasthenia Gravis
  • Obstructive disease of the gastrointestinal tract or urinary tract (obstructive uropathy)
  • Severe ulcerative colitis or reflux esophagitis
  • Unstable cardiovascular status in acute hemorrhage

Restricted and Conditional Use

Age/Condition Official Regulatory Status
Pediatric Use (6 months+) Safety and effectiveness not established by the FDA
Older Adults (Geriatric) Use with caution; may be more susceptible to effects
Pregnancy Use only if clearly needed (Benefit must outweigh risk)
Renal/Hepatic Impairment Use with caution

Eligibility is limited for populations with conditions such as coronary heart disease (CHD), hyperthyroidism, or known prostatic hypertrophy, where caution is mandated.

What should I know about interactions with other medicines?

Diclomine Interactions with other medicines and products

Interactions with diclomine are primarily defined by additive effects on the central nervous system (CNS) and anticholinergic activity, along with altered drug absorption.

Potential for Pharmacodynamic Interaction

Concomitant use with other anticholinergic agents (including certain antihistamines and phenothiazines) may result in an increased risk of side effects due to additive anticholinergic effects. This requires caution, particularly in the elderly. Similarly, co-administration with alcohol or other CNS depressants (such as certain narcotics or benzodiazepines) may enhance the effects of drowsiness or blurred vision.

Potential for Pharmacokinetic (Absorption) Interaction

Diclomine can affect gastrointestinal motility, which may alter the absorption of other medications. Specifically, the regulatory documentation highlights an interaction with slowly dissolving dosage forms of Digoxin, which could lead to an increase in serum Digoxin concentration. The effect of diclomine may be antagonized by agents that increase gastrointestinal motility, such as Metoclopramide.

Administration Requirements

Administration constraints apply to products that interfere with absorption: Antacids should not be taken simultaneously. To mitigate interference with oral absorption, the administration of diclomine and antacids must be separated by at least 2 hours.

Mechanism of Action

How Diclomine Works

Dicyclomine functions through a dual pharmacodynamic mechanism to modify the activity of the gastrointestinal (GI) smooth muscle. Its primary action involves competitive antagonism at muscarinic acetylcholine receptors (M1, M2, and M3 subtypes) situated on the GI smooth muscle cells. By occupying these binding sites, dicyclomine blocks the effects of the neurotransmitter acetylcholine, thereby inhibiting parasympathetic nervous stimulation. This molecular event suppresses the signaling cascade that typically initiates muscle contraction and glandular secretion, leading to a predictable physiological consequence of decreased smooth muscle contractility and reduced GI motility.

Simultaneously, dicyclomine exerts a secondary, musculotropic effect that operates independently of the cholinergic receptor system. This mechanism involves a direct action on the muscle cells themselves, which may include non-competitive modulation of pathways influenced by local mediators such as histamine and bradykinin. This secondary domain contributes to reduced basal tension and further decreases the overall magnitude and frequency of spontaneous muscle contractions.

Dosage and Administration Information

Administration Routes and Dosage Regimens

Diclomine is provided for oral administration in the form of tablets, capsules, and an oral solution. A separate solution is available for intramuscular (IM) injection, which is reserved for short-term use when the oral route is not feasible, and is explicitly forbidden for intravenous (IV) administration.

The standard oral dosing regimen for adults begins with 20 mg taken four times daily (QID). The dosage may be increased to 40 mg QID after approximately one week, based on individual response, up to a maximum recommended daily dose of 160 mg. The IM injection follows a QID schedule, typically using 10 mg to 20 mg per dose.


Use Conditions and Duration

Oral doses may be taken with or without food. If the liquid oral solution is used, it should be diluted with an equal volume of water immediately prior to consumption.

The IM injection route is intended for a maximum of one to two days and must be converted to oral administration as soon as the patient is able. Furthermore, if a satisfactory symptomatic response is not achieved within a two-week trial period at the prescribed dosage, the medication should be discontinued. Diclomine is contraindicated for use in infants who are less than six months of age.

Recent Clinical Evidence

Evidence for Use in Irritable Bowel Syndrome (IBS) Symptoms

The evidence for dicycloverine focuses primarily on studies in adults experiencing Irritable Bowel Syndrome (IBS) symptoms, a condition characterized by fluctuating or episodic manifestations of discomfort. Researchers evaluated changes in measures of abdominal pain and spasms using short-term Randomized Controlled Trials (RCTs). These studies monitored patient-reported outcomes and assessments of overall patient condition over brief intervals. While research provides insight into short-term changes, systematic reviews often assign a low to very low certainty grading due to the age and methodology of the core trials. The evidence contributes to the broader research landscape but does not determine whether an individual will respond similarly.

Study Duration and Evidence Gaps

A significant research limitation across the core evidence base is the short-term nature of the trials; follow-up durations were often limited to a few weeks. Long-term outcomes and patterns of continuous use over extended periods are not fully established by existing controlled trials.

Evidence in Other Situations and Special Patient Groups

Research has also been studied for its use in non-IBS conditions, including infantile colic. However, these studies are very limited and cited as having very low certainty. The majority of data is for adults. Evidence for use in pediatric populations (children and adolescents) and older adults remains insufficient.

Strength and Consistency of the Available Evidence

Scientific reviews frequently assess the quality of the dicyclomine research as low, citing research limitation frames. Findings were noted to be inconsistent in some reviews, and comparative evidence against other available treatments is often lacking in the current research literature. The results apply only to the specific populations and conditions studied.

Key Studies & References

  1. Dicyclomine for Gastrointestinal Conditions: A Review of the Clinical Effectiveness, Safety, and Guidelines (2015) - CADTH Report

Frequently Asked Questions (FAQ)

Common questions about Diclomine (FAQ)


Q: How long does the effect of Diclomine usually last?

A: Diclomine is commonly prescribed to be taken multiple times a day. While the official regulatory labeling does not specify the exact duration of action, this frequent dosing schedule is used to maintain levels of the medication, which helps manage symptoms.

Q: Does Diclomine cause drowsiness, and how bad is it usually?

A: Yes, regulatory documents list drowsiness (somnolence) as a common side effect. Other central nervous system effects, such as dizziness and blurred vision, are also commonly reported. The severity can vary by individual.

Q: Can you take Diclomine if you are already taking an antacid?

A: Antacids are generally not taken at the exact same time as Diclomine. To prevent the antacid from interfering with the proper absorption of Diclomine, official guidance recommends separating the administration of the two medications by at least 2 hours.

Q: Why do doctors tell people to be careful driving when they take Diclomine?

A: The official product warning advises caution when driving because Diclomine can produce side effects like drowsiness, dizziness, or blurred vision. Patients are warned not to engage in activities requiring complete mental alertness, such as operating a motor vehicle or machinery, until they know how the drug affects them.

Q: Does Diclomine interact with common cold or flu medicines?

A: Diclomine may have additive effects when combined with other medications that have anticholinergic effects or act as CNS depressants (meaning they slow down the brain and nervous system). This includes certain classes of ingredients often found in cold or flu remedies, such as some antihistamines.

Q: Can Diclomine affect your eyesight or cause blurry vision?

A: Blurred vision is a documented common side effect of Diclomine. Other visual effects that may be experienced include pupillary dilation and difficulty focusing on close objects.

Q: Can children take Diclomine, and if so, at what age?

A: Diclomine is contraindicated (prohibited) in infants less than 6 months of age due to the risk of serious breathing problems. For all other pediatric patients (6 months and older), the safety and effectiveness of the drug have not been established by the FDA.

Q: Does Diclomine make you feel tired or fatigued?

A: Yes, official regulatory documents list somnolence (drowsiness) as a common side effect. Additionally, asthenia (a state of weakness or lack of energy) is listed as a reported adverse reaction.

Q: Is Diclomine the same kind of drug as Bentyl?

A: Bentyl is a former brand name under which the active ingredient, Diclomine hydrochloride (Dicycloverine), was sold in the United States. Today, the medication is widely available under its generic name, Diclomine.

Q: What are the most common side effects people complain about with Diclomine?

A: The most common adverse reactions reported in clinical trials and regulatory documents are dizziness, dry mouth, and blurred vision. Other frequently reported effects include nervousness, nausea, drowsiness, and weakness.

Q: Is there a generic version of Diclomine, and is it just as effective?

A: Yes, Diclomine is widely available as a generic medication. Generic drugs are approved based on the same strict standards for quality and strength as the brand-name product.

Q: Can Diclomine cause dry mouth, and is there a way to manage it?

A: Dry mouth (xerostomia) is a very common adverse reaction because of the drug’s anticholinergic mechanism. While the official drug label confirms this side effect, it does not typically provide specific recommendations or strategies for managing it.

Q: What happens if you accidentally miss a dose of Diclomine?

A: If a dose is missed, patient information often advises taking it as soon as it is remembered. However, if it is almost time for your next scheduled dose, skip the missed one entirely. Most patient information advises against taking a double dose to make up for a missed one.

Q: Are there any specific foods or drinks you should avoid while on Diclomine?

A: You are advised to use caution with alcohol while taking Diclomine, as it can intensify drowsiness and other central nervous system effects. Furthermore, the official label includes a warning that the drug may cause heat prostration (overheating due to decreased sweating) in high environmental temperatures.

Q: Does Diclomine interact with high blood pressure medications?

A: Official labeling advises that Diclomine should be used with caution in patients with hypertension (high blood pressure). It is important to inform your healthcare provider of all current heart or blood pressure medications you are taking.

Q: Is it normal to feel a little dizzy after taking Diclomine?

A: Yes, dizziness is listed in regulatory documents as a common adverse reaction associated with Diclomine use. This is a known, expected effect of the medication.

Q: Why is Diclomine sometimes listed under different brand names?

A: Diclomine is the generic name for the active ingredient. It may be sold under various brand names by different manufacturers across the world, though the generic name is the one most often used in official documentation.

Q: Can Diclomine affect your mood or cause anxiety?

A: Diclomine can be associated with central nervous system (CNS) effects. Official reports include symptoms such as confusion, disorientation, agitation, and nervousness. These symptoms generally resolve once the drug is stopped.

Q: Are there any vitamins or supplements that interact with Diclomine?

A: While the drug label focuses on prescription drug interactions, patients are always advised to inform their healthcare provider about all medications, vitamins, and herbal supplements they are taking. This ensures that any potential interactions are considered.

Q: Is Diclomine effective for general indigestion or only for spasms?

A: According to the official indications, Diclomine is approved for the treatment of functional bowel disorders. Its purpose is specifically to relieve the painful symptoms of intestinal spasms and cramping.

Q: Can Diclomine make symptoms of acid reflux worse?

A: Diclomine is contraindicated (prohibited) in patients with reflux esophagitis (severe acid reflux). This is because the drug’s action of decreasing gut movement may relax the valve to the stomach, which could potentially worsen reflux symptoms.

Q: Is it okay to take Diclomine occasionally, or is it meant for regular use?

A: Diclomine is often used to manage the fluctuating or episodic symptoms of functional bowel disorders. For many patients, it is taken intermittently (as needed) to relieve a painful episode, after an initial period is used to assess its effectiveness.

Q: Does Diclomine work for cramping pain outside of the stomach area?

A: The regulatory indications and known pharmacological action of Diclomine are specifically focused on relieving spasms and cramping within the smooth muscle of the gastrointestinal tract (stomach and intestines).

How should Diclomine be stored and disposed of?

Storage and Disposal of Dicyclomine

Official regulatory labeling dictates specific conditions for storing and disposing of Dicyclomine to maintain stability and ensure safety.


Required Storage Conditions

Dicyclomine formulations must be stored at Controlled Room Temperature, which is 20°C to 25°C (68°F to 77°F). Storage must protect the medicine from excessive heat, and liquid forms should be kept from freezing. Packaging rules require oral solutions to be dispensed in a tight container and protected from light and moisture.


Safety and Disposal

For child safety, the medication must be kept out of the reach and sight of children, and the oral solution requires a child-resistant closure. Unused or expired Dicyclomine must be disposed of in accordance with local requirements; patients should ask a healthcare professional for guidance on proper disposal procedures.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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