Cyclopam Suspension

Indications

• Symptomatic relief of gastrointestinal disorders characterized by smooth muscle spasm
• Irritable bowel syndrome
• Acute spasm in diagnostic procedures

Dosage

Children: Child 12–17 years: 10–20 mg three times a day. Child 2–4 years: 5 mg three to four times a day. Child 1 month–1 year: 300–500 micrograms/kg three to four times a day (maximum per dose 5 mg).

Adults: 10–20 mg three times a day, increased if necessary up to 20 mg four times a day; maximum daily dose is 100 mg.

Mechanism of action

Dicycloverine hydrochloride functions as an antimuscarinic by blocking the action of acetylcholine at muscarinic receptors in the smooth muscles of the gastrointestinal tract. This inhibition results in reduced motility and relaxation of the gastrointestinal smooth muscle, alleviating spasms and cramping.

Pharmacodynamics

The primary effect of dicycloverine hydrochloride is the reduction of gut motility due to its antimuscarinic properties. It has a less pronounced antimuscarinic action compared to atropine but may also exhibit some direct relaxant effects on smooth muscle. This dual action helps in relieving abdominal pain associated with smooth muscle spasms.

Pharmacokinetics

Dicycloverine hydrochloride is well absorbed from the gastrointestinal tract. Its onset of action typically occurs within 30 minutes to 1 hour after oral administration, with a duration of effect lasting several hours. The drug undergoes hepatic metabolism and has a variable elimination half-life. Its clearance may be affected by renal function, and caution is advised in patients with renal impairment.

Contra-indications

• Hypersensitivity to dicycloverine or any of its components
• Glaucoma
• Myasthenia gravis
• Severe ulcerative colitis
• Obstructive uropathy
• Severe gastrointestinal obstruction

Adverse effects

• Dry mouth
• Dizziness
• Constipation
• Drowsiness
• Nausea
• Blurred vision
• Urinary retention
• Increased heart rate
• Skin reactions (e.g., flushing, urticaria)

Interactions

• Anticholinergic drugs may enhance effects
• Potentiation of the effects of other CNS depressants such as alcohol
• Antacids containing aluminium may increase risk of toxicity

Precautions

• Use with caution in patients with renal impairment
• May exacerbate conditions like glaucoma and myasthenia gravis
• Monitor for signs of anticholinergic syndrome

Pregnancy

Not known to be harmful; manufacturer advises use only if essential.

Breast-feeding

Avoid; present in milk with potential for causing apnoea in infants.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Oral solution: Dicycloverine hydrochloride 500 micrograms per 1 ml
• Combination products containing aluminium hydroxide and simeticone

Indications

• Irritable bowel syndrome (IBS)
• Gastrointestinal spasm
• Abdominal cramping

Dosage

Children: Refer to the BNF for Children for specific dosing information.

Adults: 20 mg to 40 mg orally, 4 times daily or 10 mg to 20 mg by intramuscular injection, as needed. Do not administer intravenously.

Mechanism of action

Dicyclomine achieves its action partially through direct antimuscarinic activity at the M1, M3, and M2 receptors, and partially through antagonism of bradykinin and histamine. It non-competitively inhibits the action of bradykinin and histamine, leading to a direct relaxant effect on smooth muscle, specifically reducing the strength of contractions observed in ileal spasms. Its major action appears to be a nonspecific direct relaxant effect on smooth muscle rather than competitive antagonism of acetylcholine.

Pharmacodynamics

Dicyclomine is classified as an anticholinergic agent that relaxes the smooth muscles of the intestines. Its duration of action is relatively short, leading to a typical administration schedule of four times daily, with doses ranging from 20-40 mg orally or 10-20 mg via intramuscular injection. It is important to note that dicyclomine should not be administered intravenously.

Pharmacokinetics

Dicyclomine is absorbed through the gastrointestinal tract and metabolized in the liver. The onset of action occurs within 1 hour of administration, with peak effects seen at approximately 1-2 hours. The elimination half-life varies, but it is generally in the range of 1-2 hours, necessitating multiple daily doses to maintain therapeutic levels. The drug is primarily excreted in urine as metabolites.

Contra-indications

• Glaucoma
• Myasthenia gravis
• Severe ulcerative colitis
• Obstructive uropathy
• Obstructive gastrointestinal disease
• Tachyarrhythmias

Adverse effects

• Dizziness
• Dry mouth
• Nausea
• Vomiting
• Constipation
• Blurred vision
• Tachycardia
• Urinary retention

Interactions

• Clozapine (unknown additive effect)
• Second-generation antipsychotics (unknown additive effect)

Precautions

• Use with caution in patients with renal impairment
• Use with caution in patients with hepatic impairment
• Caution in elderly patients due to increased risk of sensitivity to anticholinergic effects

Pregnancy

Dicyclomine is not recommended during pregnancy due to potential risk to the fetus.

Breast-feeding

Dicyclomine is excreted in breast milk and may cause adverse effects in nursing infants; use with caution.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.

Formulations

• Oral tablet (20 mg, 40 mg)
• Injection (10 mg, 20 mg)

Indications

• Flatulence
• Bloating
• Gastroesophageal reflux disease
• Functional dyspepsia

Dosage

Children: For children, refer to the BNF for Children for specific dosing recommendations.

Adults: The usual adult dose is 40 to 125 mg taken after meals and at bedtime, as needed.

Mechanism of action

Simethicone is a surfactant that decreases the surface tension of gas bubbles in the gastrointestinal tract, facilitating their expulsion. It acts by forming a film of low surface tension that promotes the coalescence of mucus-surrounded gas bubbles, allowing for easier passage of gas.

Pharmacodynamics

Simethicone decreases the surface tension of gas bubbles in the gastrointestinal tract, facilitating their expulsion. Its effects are generally short-lived, as it is typically administered as needed. The therapeutic index is wide since it is not absorbed systemically, making it safe for use in various patient populations.

Pharmacokinetics

Simethicone is not systemically absorbed following oral administration, which contributes to its safety profile. Due to its lack of systemic absorption, specific pharmacokinetic parameters such as half-life, clearance, and volume of distribution are not applicable.

Pregnancy

Simethicone can be used during pregnancy as there are no known risks associated with its use.

Breast-feeding

Simethicone is considered safe to use during breastfeeding, as it is not absorbed systemically.

Storage

Store in a cool, dry place, away from direct sunlight. Keep out of reach of children.

Formulations

• Oral suspension
• Chewable tablets
• Soft gels

Mechanism of action

Dicyclomine achieves its action partially through direct antimuscarinic activity of the M1, M3, and M2 receptors; and partially through antagonism of bradykinin and histamine. Dicyclomine non-competitively inhibits the action of bradykinin and histamine, resulting in direct action on the smooth muscle, and decreased strength of contractions seen in spasms of the ileum. ...MAJOR ACTION APPEARS TO BE NONSPECIFIC DIRECT RELAXANT ACTION ON SMOOTH MUSLCE RATHER THAN COMPETITIVE ANTAGONISM OF ACH.

Pharmacodynamics

Dicyclomine is an anticholinergic drug used to relax the smooth muscles of the intestines. It's duration of action is not especially long as it is usually taken 4 times daily with individual doses of 20-40mg orally or 10-20mg by intramuscular injection. Dicyclomine should not be administered intravenously.

Mechanism of action

Simethicone is a surfactant that decreases the surface tension of gas bubbles in the gastrointestinal tract, more easily allowing gas to exit the body. The clinical use of simethicone is based on its antifoam properties. Silicone antifoams spread on the surface of aqueous liquids, forming a film of low surface tension and thus causing collapse of foam bubbles. Simethicone reportedly allows mucus-surrounded gas bubbles in the GI tract to coalesce and be expelled.

Pharmacodynamics

Simethicone decreases the surface tension of gas bubbles in the gastrointestinal tract, facilitating their expulsion. It has a short duration of action as it is generally given as needed, and a wide therapeutic index as it is not systemically absorbed.