Usage
- Methylpolysiloxane is prescribed for the symptomatic relief of excess gas in the gastrointestinal tract, including bloating, discomfort, and flatulence. It is also used to eliminate gas bubbles before diagnostic procedures like endoscopy and roentgenography.
- Pharmacological Classification: Antiflatulent, antifoaming agent.
- Mechanism of Action: Methylpolysiloxane reduces the surface tension of gas bubbles in the GI tract, causing them to coalesce into larger bubbles that can be more easily expelled. It forms a protective layer on the gastric mucosa, offering some protection against irritants. It does not affect gastric pH or drug absorption.
Alternate Names
- Simethicone
- Dimethylpolysiloxane
- Activated methylpolysiloxane
- Silicone antifoam
- Polydimethylsiloxane
- Brand Names: Gascon, Polysan, Polyfort
How It Works
- Pharmacodynamics: Methylpolysiloxane works locally in the GI tract to reduce the surface tension of gas bubbles. It has no systemic effects as it is not absorbed.
- Pharmacokinetics: Methylpolysiloxane is not absorbed from the GI tract. It passes through the digestive system unchanged and is eliminated in the feces. It does not interact with CYP enzymes. About 50% of it is excreted in the feces within 6 hrs, and 90% within 12-24 hours
- Mode of Action: Methylpolysiloxane is a surfactant that works physically to break down gas bubbles, not through receptor binding, enzyme inhibition, or neurotransmitter modulation.
- Elimination Pathways: Primarily fecal excretion.
Dosage
Standard Dosage
Adults:
- 40-125 mg orally after meals and at bedtime as needed.
- One tablespoon (containing a specific concentration, refer to product information) three times daily before meals, repeatable as needed.
- 120-240 mg daily divided into three doses after or between meals
- The dosage may be adjusted based on the formulation and individual patient response.
Children:
- 6-12 years: 5ml after meals and at bedtime.
- Pediatric dosage varies depending on the formulation; consult product information.
- Use in children under 5 is generally not recommended unless directed by a physician.
Special Cases:
- Elderly Patients: No specific dosage adjustments are usually required.
- Patients with Renal Impairment: Use with caution in patients with impaired renal function.
- Patients with Hepatic Dysfunction: No specific dosage adjustments are typically needed.
- Patients with Comorbid Conditions: No explicit dosage adjustments are defined.
Clinical Use Cases
Specific dosage adjustments for clinical settings (intubation, surgical procedures, ICU, etc.) are not well-defined. The standard recommendations generally apply, with adjustments based on clinical judgment and individual patient needs.
Dosage Adjustments
Dose modification is not typically necessary, except in cases of renal impairment where caution is advised.
Side Effects
Common Side Effects
- Mild and infrequent. May include diarrhea, constipation, nausea, stomach ache, dyspepsia, gastric irritation.
Rare but Serious Side Effects
- No serious side effects have been reported.
Long-Term Effects
- No long-term adverse effects associated with methylpolysiloxane use have been identified.
Adverse Drug Reactions (ADR)
- No significant ADRs have been documented.
Contraindications
- Hypersensitivity to simethicone or any component of the formulation.
Drug Interactions
- Methylpolysiloxane may reduce the absorption of some medications, such as ketoconazole, itraconazole, and possibly others. Separate the administration of other drugs by 2-3 hours.
- It may also interact with phosphate supplements and sodium polystyrene sulfonate.
- Avoid alcohol intake as it might potentiate drowsiness or other adverse effects.
- It may react with certain other drugs including digoxin, iron, pazopanib, tetracycline, and quinolone antibiotics.
Pregnancy and Breastfeeding
- Pregnancy: Although no harmful effects on the fetus have been observed in animal studies, there are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus.
- Breastfeeding: The safety of methylpolysiloxane during breastfeeding has not been established. It is unknown if the drug is excreted in human milk. Exercise caution when administering to breastfeeding mothers.
Drug Profile Summary
- Mechanism of Action: Reduces surface tension of gas bubbles, causing them to coalesce for easier expulsion.
- Side Effects: Generally mild and infrequent, including diarrhea, constipation, nausea, stomach pain.
- Contraindications: Hypersensitivity to simethicone.
- Drug Interactions: May interfere with the absorption of certain medications, such as antifungals.
- Pregnancy & Breastfeeding: Limited safety data; use with caution.
- Dosage: Adults: 40-125 mg after meals and at bedtime. Children: Consult product information.
- Monitoring Parameters: Not typically required as the drug is not systemically absorbed.
Popular Combinations
- Often combined with antacids (aluminum hydroxide, magnesium hydroxide) to address both gas and heartburn/indigestion.
- Can be found combined with itopride for functional dyspepsia.
Precautions
- General Precautions: Screen for hypersensitivity. Use with caution in patients with renal impairment.
- Specific Populations: Consult a physician regarding use during pregnancy and breastfeeding. No specific precautions for children or elderly, aside from standard dosing recommendations. No specific precautions for menstruating individuals.
- Lifestyle Considerations: Avoid alcohol as it may enhance drowsiness. No restrictions on driving or operating machinery are generally associated with its use.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Methylpolysiloxane?
A: Adults: 40-125 mg orally after meals and at bedtime, as needed. Pediatric dosage varies; consult product information.
Q2: What are the common side effects?
A: Side effects are generally mild and infrequent, and may include diarrhea, constipation, nausea, and stomach discomfort.
Q3: Is Methylpolysiloxane safe during pregnancy?
A: Consult with a physician. Use only if clearly needed.
Q4: Can I take Methylpolysiloxane while breastfeeding?
A: Consult with a physician. Safety during breastfeeding is not fully established.
Q5: How does Methylpolysiloxane work?
A: It reduces surface tension of gas bubbles, causing them to combine into larger bubbles, which are easier to eliminate.
Q6: Does Methylpolysiloxane interact with other medications?
A: It may reduce the absorption of certain drugs like some antifungals, and there is potential for interactions with a few others. Consult a doctor or pharmacist about potential interactions with concomitant medications. Separate administration of other drugs by 2-3 hours.
Q7: Are there any contraindications for using Methylpolysiloxane?
A: Yes, known hypersensitivity to simethicone is a contraindication.
Q8: Can Methylpolysiloxane be used in children?
A: Yes, but with caution, and at lower doses than in adults. Consult product specific information for pediatric dosage.
Q9: How long does it take for Methylpolysiloxane to work?
A: Onset of action is not precisely defined, but relief is generally experienced relatively quickly.
Q10: Is Methylpolysiloxane addictive?
A: No, it is not known to be addictive.
