Gas-X

Other Agents for Functional Bowel Disorders

Chewable tablets:
Chew tablet well before swallowing.
 
Softgel capsules:
Swallow whole with water; do not chew.

Simethicone oral suspension:
Shake well prior to each administration.
Measure dose with provided calibrated dropper or other oral calibrated measuring device.
For infants, administer liquid toward the inner cheek of infant.
To ease administration, drops may be mixed with water, infant formula, or other liquids.

eructation / Early / 1.0-10.0
flatulence / Early / 1.0-10.0

Equalizer Gas Relief, Gas Free, Gas Relief, Gas-X, Gas-X Extra Strength, Gas-X Infant, Gas-X Ultra Strength, GasAid, Genasyme, Gerber Gas Relief, Infantaire, Infants' Gas Relief, Little Remedies for Tummys, Mylanta Gas, Mylicon, Mytab Gas, PediaCare Infant's Gas Relief, Phazyme

OTC

Oral antiflatulent agent
Used in nonprescription products to relieve excess gas in the digestive tract in adult and pediatric patients
Used in radiographic and other GI procedures to enhance gastrointestinal visibility and reduce gas shadowing

40 to 360 mg PO per dose after meals and at bedtime, as needed, is the non-prescription dosing. Usual Max: 500 mg/24 hours except under the advice and supervision of a physician.

40 mg to 160 mg PO per dose after meals and at bedtime, as needed, is the non-prescription dosing. Usual Max: 480 mg/day PO unless otherwise directed by a physician.

40 mg PO per dose after meals and at bedtime as needed, or as directed by a physician (non-prescription dosing). Usual Max: 480 mg/day PO unless otherwise directed by a physician.

20 mg PO per dose after meals and at bedtime as needed, or as directed by a physician (non-prescription dosing). Usual Max: 240 mg/day (12 doses) PO unless otherwise directed by a physician. Efficacy for infant colic is questionable.

Doses of 80 to 105 mg PO 3 times per day have been used. Simethicone was more effective than cisapride in the first 2 weeks of dyspepsia treatment for symptomatic relief in one trial. Routine use is not recommended; simethicone has not been included as a standard treatment option in dyspepsia guidelines due to lack of sufficient, high-quality data.

Simethicone has a long history of use in gastrointestinal (GI) diagnostic procedures. Single doses of 40 mg to 133 mg PO given 20 minutes to 1 hour prior to various endoscopy, colonoscopy, or GI radiographic procedures are most common. Simethicone oral suspension drops are most commonly used. Various protocols are reported, depending on the procedure and institution. Most publications/guidelines agree that the addition of simethicone prior to standard preparation regimens may aid visualization during magnetically controlled capsule endoscopy, upper gastroscopy or endoscopy, colonoscopy, GI radiography, and selected other GI procedures. The effect on diagnostic yield is controversial. Also, simethicone residue despite endoscope reprocessing has been reported.

†Indicates off-label use

No dosage adjustments are needed.

No dosage adjustments are needed.

Levothyroxine: (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after a dose of simethicone. Concurrent use may reduce the efficacy of levothyroxine by binding and delaying or preventing oral absorption, potentially resulting in hypothyroidism. Simethicone has been reported to chelate oral levothyroxine within the GI tract when administered simultaneously, leading to decreased thyroid hormone absorption.
Levothyroxine; Liothyronine (Porcine): (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after a dose of simethicone. Concurrent use may reduce the efficacy of levothyroxine by binding and delaying or preventing oral absorption, potentially resulting in hypothyroidism. Simethicone has been reported to chelate oral levothyroxine within the GI tract when administered simultaneously, leading to decreased thyroid hormone absorption.
Levothyroxine; Liothyronine (Synthetic): (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after a dose of simethicone. Concurrent use may reduce the efficacy of levothyroxine by binding and delaying or preventing oral absorption, potentially resulting in hypothyroidism. Simethicone has been reported to chelate oral levothyroxine within the GI tract when administered simultaneously, leading to decreased thyroid hormone absorption.
Liothyronine: (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after a dose of simethicone. Concurrent use may reduce the efficacy of levothyroxine by binding and delaying or preventing oral absorption, potentially resulting in hypothyroidism. Simethicone has been reported to chelate oral levothyroxine within the GI tract when administered simultaneously, leading to decreased thyroid hormone absorption.
Thyroid hormones: (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after a dose of simethicone. Concurrent use may reduce the efficacy of levothyroxine by binding and delaying or preventing oral absorption, potentially resulting in hypothyroidism. Simethicone has been reported to chelate oral levothyroxine within the GI tract when administered simultaneously, leading to decreased thyroid hormone absorption.

Equalizer Gas Relief/Gas Relief/Gas-X/Gas-X Infant/Genasyme/Gerber Gas Relief/Infantaire/Infants' Gas Relief/Little Remedies for Tummys/Mylicon/PediaCare Infant's Gas Relief/Simethicone Oral Drops: 0.3mL, 20mg
Gas Free/Gas Relief/Gas-X/Gas-X Extra Strength/Gas-X Ultra Strength/Mylanta Gas/Phazyme/Simethicone Oral Cap: 125mg, 180mg, 250mg
Gas Relief/Gas-X/Gas-X Extra Strength/Genasyme/Mylanta Gas/Mytab Gas/Phazyme/Simethicone Oral Tab Chew: 80mg, 125mg
Gas-X Oral Film: 62.5mg

500 mg/day PO for nonprescription use.

500 mg/day PO for nonprescription use.

480 mg/day PO.

2 to 12 years: 480 mg/day PO.
1 year: 240 mg/day PO.

240 mg/day PO.

As an antiflatulent, simethicone has been shown in vitro to disperse and prevent the formation of mucus-surrounded gas pockets in the GI tract. Changing the surface tension of the gas bubble prevents these pockets. The gas bubbles coalesce and are more quickly eliminated by flatus, belching, or absorption into the bloodstream. These actions in vivo have not been clearly established. Additionally, simethicone exhibits in vitro activity against Helicobacter pylori.
 
Simethicone also reduces gas bubbles that obstruct visualization in various gastrointestinal procedures such as radiography, gastroscopy, and colonoscopy. For example, simethicone-coated cellulose suspension (e.g., SonoRx) acts to absorb and disperse gas within the bowel lumen resulting in reduced shadowing during ultrasound imaging.

Both simethicone and simethicone-coated cellulose suspension are administered orally. Simethicone is physiologically inert and not systemically absorbed. A study in volunteers measuring silicon in the blood (as the surrogate marker for simethicone) noted that blood and urine levels of silicone were similar at baseline and after receiving SonoRx or vehicle control. This suggests minimal systemic absorption of simethicone. Similarly, the body does not metabolize simethicone and cellulose. Simethicone and cellulose are both excreted unchanged in the feces. Simethicone is not known to interfere with gastric secretion or nutrient absorption; however, this medicine is usually taken after at least 4 hours of fasting. SonoRx may color the stool orange until elimination is complete, typically 24 to 48 hours.

Simethicone is physiologically inert and not systemically absorbed.

Epidemiologic evidence during human pregnancy shows no difference in outcomes between simethicone exposed and nonexposed pregnancies, and there is a low risk for use during endoscopy or as an antiflatulent because it is not systemically absorbed. In normal therapeutic doses for the treatment of occasional gas, the drug is also considered low risk.

Studies have not been conducted to determine if simethicone is excreted in human milk. However, due to the fact that simethicone is not absorbed systemically, it seems unlikely that simethicone would be excreted in the milk of breast-feeding women. Problems in infants have not been documented.