Dicycloverine for Functional Bowel Disorders - A Complete Guide

Overview:

Dicycloverine (Dicycloverine hydrochloride) is a drug belonging to the antimuscarinic group and aims to block the action of acetylcholine neurotransmitters. By doing so, the drug reduces the contraction of muscles in the intestine, thus relieving spasms and associated discomfort. Dicycloverine is prescribed for managing irritable bowel syndrome by exerting its antispasmodic action and causing intestinal smooth muscle relaxation. Dicycloverine was approved for use on May 11th, 1951, by the United States Food and Drug Administration (USFDA).

Dosage and Route of Administration:

Dicycloverine hydrochloride can be administered through oral and intramuscular routes.

Oral Route:

• The starting dose of Dicycloverine commonly indicated to treat irritable bowel syndrome and functional bowel is 20 milligrams (mg) per day. The drug should be taken four times a day.

• This dose is increased to 40 mg per day after one week of the initial dosage.

The total dose per day should not exceed more than 80 mg per day. Dicyloverine is generally taken before meals.

Intramuscular Route:

The intramuscular route of administration is recommended only when patients cannot go for oral administration. The dosage given in such a case is 10 to 20 mg four times a day, based on the patient's needs.

Indications:

• Dicycloverine is commonly prescribed to mitigate symptoms caused by irritable bowel syndrome, like pain in the abdominal area, cramping, and discomfort. It functions by relaxing the smooth intestinal muscles. The drug should only be given to individuals above six months of age.

• Dicycloverine may be used to relieve symptoms in various functional gastrointestinal disorders where muscle spasms play a role, such as functional dyspepsia (a chronic disease causing aches and discomfort in the upper abdominal region and is caused by the presence of ulcers or inflammation).

Contraindications:

• Infants below six months of age are not indicated for treatment with Dicyloverine.

• Individuals with any obstruction within the gastrointestinal tract (intestinal obstruction) are contraindicated.

• Giving Dicycloverine to individuals with myasthenia gravis (An autoimmune neuromuscular condition that affects the acetylcholine receptors) can further exacerbate muscle weakness and fatigue. Hence, Dicycloverine is contraindicated.

• Dicycloverine is contraindicated in individuals with severe ulcerative colitis.

• The medication should be used with caution in individuals with glaucoma (a condition where the internal pressure of the ocular cavity is increased), as antimuscarinic drugs like Dicycloverine may increase intraocular pressure.

• For people with unstable cardiovascular conditions or any such previous history, Dicycloverine is contraindicated.

• In people with obstructive uropathy (a condition where there is a buildup of urine due to obstruction in the urinary tract and system), Dicycloverine is contraindicated.

• Dicycloverine is also not indicated for use in people with reflux esophagitis (esophageal inflammation due to regurgitation or reflux of the gastrointestinal contents).

For Patients:

What Is a Functional Bowel Disorder?

Functional bowel disorders are a group of gastrointestinal conditions characterized by abnormalities in the function of the digestive tract without any kind of identifiable structural or biochemical abnormalities. Unlike inflammatory bowel diseases like Crohn's disease or ulcerative colitis (inflammation and ulceration of the colon), functional bowel disorders do not have visible signs of inflammation or damage upon examination. Common examples include irritable bowel syndrome (IBS), functional dyspepsia (dysfunctional digestion), and functional constipation.

What Are the Symptoms of Functional Bowel Disorders?

• Pain in the abdominal area that is persistent for a long time.

• Bowel movements become altered. This can cause constipation, diarrhea, or both. Some individuals may experience urgency or a feeling of incomplete evacuation.

• After food intake, people may feel bloated or distended.

• For those with functional dyspepsia, symptoms may include early satiety and fullness.

All such symptoms can be experienced by the individual once there is a triggering factor like stress or hormonal change.

Why Is Dicycloverine Prescribed for Functional Bowel Disorders?

Dicycloverine is commonly prescribed for functional bowel disorders like irritable bowel syndrome because it has antispasmodic properties. As an antimuscarinic medication, Dicycloverine works by blocking the action of acetylcholine (a neurotransmitter involved in smooth muscle contraction). In the context of functional bowel disorders, particularly IBS, abnormal smooth muscle contractions in the gastrointestinal tract contribute to symptoms like pain and cramping in the abdominal area.

Dicycloverine, an antimuscarinic medication, works by binding to muscarinic receptors on the smooth muscle cells. Muscarinic receptors are receptors that respond to acetylcholine. By blocking these receptors, Dicycloverine inhibits the stimulatory effects of acetylcholine on smooth muscle, leading to muscle relaxation. This relaxation helps to reduce the spasms and hyperactivity of the bowel. While it does not address the exact underlying cause of functional bowel disorders, Dicycloverine provides symptomatic relief and is often part of a comprehensive treatment approach.

What Are the Side Effects of Taking Dicycloverine?

• Dizziness is the most common side effect noticed in people taking Dicycloverine.

• Dicycloverine can reduce saliva production, leading to a dry sensation in the mouth.

• Blurred vision or difficulty to focus may be encountered by some people.

• An upset stomach or an urge to vomit is noticed in some individuals.

• In some cases, Dicycloverine can lead to constipation.

• People may also experience drowsiness (somnolence) after taking Dicycloverine.

• Muscle weakness, fatigue, or lack of energy is a common side effect.

• Palpitations have been noticed in some cases, especially in individuals with a history of cardiovascular disorders.

• Reduced sweating with fever is observed.

• In rare cases, allergic responses and nasal congestion have been seen.

How Should Dicycloverine Be Taken for Functional Bowel Disorders?

Dicycloverine is available in the form of tablets and capsules for oral intake. The dosage options include 10 mg and 20 mg respectively.

The general recommended dosage for treating functional bowel disorders (irritable bowel syndrome) is 20 mg four times a day for one week. This is followed by increasing the dosage to 40 mg four times a day after the first week. The drug is usually recommended to be taken before meals and bedtime. If a particular dose is missed, skipping that dose and continuing with the remaining dose as per schedule is recommended. The ideal temperature to store Dicycloverine is around 30 degrees Celsius (86 degrees Fahrenheit). Care should be taken not to expose Dicycloverine to high temperature or heat.

Dicycloverine is also available for use in syrup forms. It contains 10 mg of Dicycloverine hydrochloride in one tablespoon of syrup (five milliliters).

If patients are unable to take Dicycloverine through oral means, the prescribing doctor may advise intramuscular administration (injecting Dicycloverine through muscles). For this parenteral administration, the dosage is 20 mg four times daily.

What Are the Precautions to Be Taken Before Taking Dicycloverine?

• Any pre-existing medical conditions like myasthenia gravis, ocular issues, cardiac problems, prostatic hypertrophy (increase in size of prostate gland causing urinary blockage), and urinary retention should be informed to the doctor as Dicycloverine is contraindicated in such cases.

• Individuals with glaucoma should exercise caution, as Dicycloverine can increase intraocular pressure.

• If there is reduced sweating along with fever after drug intake, it should be informed immediately.

• Individuals suffering from obstruction in the intestine or esophageal inflammation should inform the doctor beforehand.

• In case there is overdosing of the drug, there can be exaggerated muscle weakness that can result in paralysis. Hence, immediate action should be taken to get medical intervention.

• Patients taking Dicycloverine are not advised to drive as there can be drowsiness during the journey.

For Doctors:

Clinical Pharmacology:

Dicycloverine is an antimuscarinic medication with clinical relevance in the management of gastrointestinal disorders, particularly those involving smooth muscle spasms. As an antispasmodic agent, Dicycloverine acts by competitively inhibiting acetylcholine at muscarinic receptors, leading to smooth muscle relaxation in the gastrointestinal tract. This results in the alleviation of symptoms associated with conditions like irritable bowel syndrome, where abnormal smooth muscle contractions contribute to abdominal pain and cramping.

Drug Ingredients:

• Active Ingredient: Dicycloverine hydrochloride.

• Inactive Ingredients: Lactose, calcium phosphate, magnesium stearate, and gelatin are used.

Half-Life:

The half-life of Dicycloverine is around one to 1.5 hours.

Pharmacokinetics:

• Absorption: After oral intake, the drug Dicycloverine is well-absorbed and undergoes relatively rapid absorption in the gastrointestinal tract. Peak plasma concentrations of Dicycloverine are typically reached within one to two hours following oral intake.

• Metabolism: Dicycloverine is metabolized in the liver by the cytochrome P450 enzyme system. The specific isoform of cytochrome P450 involved in the metabolism of Dicycloverine is CYP2D6.

• Distribution: Once absorbed into the bloodstream after oral administration, Dicycloverine is likely to be distributed to various tissues, including those in the gastrointestinal tract, where it exerts its pharmacological effects on smooth muscles.

• Excretion: Approximately 80 percent of Dicycloverine is excreted through urine. Less than eight percent of the drug is excreted through feces.

Pharmacodynamics:

Dicycloverine exerts its pharmacodynamic effects primarily as an antimuscarinic agent and smooth muscle relaxant. As an antimuscarinic, it competitively hinders the activity of acetylcholine in the smooth muscle cells (at the muscarinic receptors) of the gastrointestinal tract. By blocking these receptors, Dicycloverine interrupts the normal signaling pathways that lead to excessive smooth muscle contractions. This results in the relaxation of smooth muscles, specifically in the intestinal tract, and relieves the symptoms associated with functional bowel disorders.

Dicycloverine exerts its actions by acting on M1, M2, and M3 smooth muscle receptors. It also inhibits the action of bradykinin and histamine, which are responsible for muscle contraction. By doing so, the muscular spasm is reduced.

Clinical Toxicity:

• Dicycloverine can cause disturbances in vision, and excessive intake may exacerbate this effect.

• Anticholinergic medications like Dicycloverine can lead to a dry mouth, and toxicity may intensify this symptom.

• Excessive dose may result in the incidence of symptoms such as drowsiness, dizziness, confusion, and even hallucinations.

• In some cases, an overdose of Dicycloverine may cause tachycardia, palpitations, and other cardiovascular effects.

• Severe cases of toxicity may lead to difficulty in passing urine (urinary retention).

• Antimuscarinic medications, including Dicycloverine, may impair the body's ability to regulate temperature, leading to heat intolerance.

• Hypersensitivity to Dicycloverine manifests as rash, erythema, and in rare cases, can lead to angioedema or anaphylactic shock.

Drug Interactions:

• Combined use of Dicycloverine with other medications possessing anticholinergic properties may enhance the overall antimuscarinic effects, thus causing increased adverse effects such as dry mouth, blurred vision, and constipation.

• Dicycloverine's potential for causing drowsiness may be enhanced when combined with other drugs that have CNS depressant effects, such as sedatives and tranquilizers.

• The antiarrhythmic medication Quinidine may interact with Dicycloverine, leading to an increased risk of antimuscarinic effects and potential cardiac effects.

• Using Dicycloverine with antiglaucoma medications can further increase intraocular pressure.

• Antacids should not be given along with Dicycloverine.

• The antiviral and antiparkinsonian medication Amantadine may interact with Dicycloverine, potentially leading to increased antimuscarinic side effects.

What Are the Precautions to Be Taken Before Prescribing Dicycloverine?

• Dicycloverine should be avoided for patients with myasthenia gravis as it can exacerbate muscle weakness and cause paralysis.

• Dicycloverine should be used cautiously in patients with cardiovascular diseases along with functional bowel disorders (due to the risk of palpitations and arrhythmias).

• Intramuscular injections should be administered properly, and injecting Dicycloverine through veins can cause complications like thrombophlebitis and thrombosis, and in rare cases, it can result in reflex sympathetic dystrophy syndrome.

• Dicycloverine should be avoided in patients with prostate hypertrophy as it can cause urinary retention.

• Adjustments may be necessary for individuals with liver and kidney dysfunction.

• If there is an incidence of fever with decreased sweating (heat stroke), the drug Dicycloverine should be discontinued immediately.

• Dicycloverine can alter the gastrointestinal motility. Thus, it should not be used in people with ulcerative colitis and intestinal obstruction.

Guidelines for Specific Population:

• Pregnant and Lactating Population: Dicycloverine is considered a category B drug, and it is generally not indicated for pregnant people. There is evidence of excretion of Dicycloverine through breast milk. Hence, Dicycloverine should not be given to lactating mothers as it can cause complications for the babies.

• Pediatric Population: Dicycloverine is indicated to treat functional bowel disorders for children above six months of age. It is contraindicated for babies younger than six months.

• Geriatric Population: There is no need to alter the dose of Dicycloverine in healthy elders. However, dose adjustments are necessary for elderly adults with impaired hepatic and renal function.

Overall, Dicycloverine is an antimuscarinic medication prescribed for functional bowel disorders, such as irritable bowel syndrome. As an antispasmodic agent, it inhibits acetylcholine at muscarinic receptors, leading to smooth muscle relaxation in the gastrointestinal tract. This alleviates symptoms like abdominal pain and cramping associated with hyperactive smooth muscle contractions. Dicycloverine's clinical efficacy lies in its ability to provide symptomatic relief rather than addressing the root cause of functional bowel disorders.