Brand Name: Phazyme, Mi-Acid, Gas Relief, Mytab Gas, Gas-X, Gas-X Extra Strength, Mylanta, Mygel, DiGel, Gelusil, Rulox
Generic Name: Aluminum Hydroxide/Magnesium Hydroxide/Simethicone
Drug Class: Antacids, Combos
What is simethicone, and how does it work (mechanism of action)?
Simethicone is an anti-gas (anti-flatulence) medication. It acts in the stomach and intestines to change the surface tension of gas bubbles, enabling their breakdown and the formation of larger bubbles. In this way, it is believed that gas can be eliminated more easily by belching or passing flatus. Simethicone was approved by the FDA in 1952.
Do I need a prescription for simethicone?
No
What are the uses for simethicone?
Simethicone relieves abdominal pain due to excessive gas in the digestive tract. It also is given to patients undergoing upper abdominal ultrasound imaging.
What are the side effects of simethicone?
Common side effects of simethicone may include:
Serious side effects of simethicone include:
- rebound hyperacidity,
- aluminum-intoxication,
- low blood phosphates (hypophosphatemia),
- chalky taste,
- constipation (this could lead to hemorrhoids or bowel obstruction),
- fecal impaction,
- stomach cramps,
- milk-alkali syndrome, and
- softening of the bones.
What is the dosage for simethicone?
- The recommended dose for relieving gas is 40-125 mg 4 times daily after meals and at bedtime.
- The dosage can be mixed with water, infant formula, or other liquids for use in small children.

SLIDESHOW
Super Tips to Boost Digestive Health: Bloating, Constipation, and More See SlideshowWhich drugs or supplements interact with simethicone?
- Simethicone has severe interactions with the following drug:
- pazopanib
- raltegravir
- Simethicone has serious interactions with the following drugs:
- atazanavir
- baloxavir marboxil
- ciprofloxacin
- demeclocycline
- dapsone
- dasatinib
- demeclocycline
- digoxin
- doxycycline
- eltrombopag
- fleroxacin
- infigratinib
- gemifloxacin
- sotorasib
- Aluminum Hydroxide/Magnesium Hydroxide/Simethicone has moderate interactions with at least 132 other drugs.
- Aluminum Hydroxide/Magnesium Hydroxide/Simethicone has minor interactions with at least 59 other drugs.
This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, or if you have health questions or concerns.
Is simethicone safe to take if I'm pregnant or breastfeeding?
What else should I know about simethicone?
What preparations of simethicone are available?
- Liquid drops: 40 mg per 0.6 ml. Chewable tablets: 40, 80 and 125 mg. Capsules: 125 and 180 mg.
How should I keep simethicone stored?
- Preparations should be stored at room temperature, 15 C - 30 C (59 F - 86 F).
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Summary
Simethicone (Phazyme, Mi-Acid, Gas Relief, Mytab Gas, Gas-X, Gas-X Extra Strength, Gas-X Ultra Strength) is an antigas medication used to relieve abdominal pain caused by excessive gas. Review side effects, drug interactions, dosage, and pregnancy safety information prior to taking this medication.
Multimedia: Slideshows, Images & Quizzes
Related Disease Conditions
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Intestinal Gas and Gas Pain
Intestinal gas and painful bloating are common. Learn about what causes gas pain and how eliminating certain foods from your diet can help relieve symptoms.
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Heartburn
Heartburn is a burning sensation experienced from acid reflux (GERD). Symptoms of heartburn include chest pain, burning in the throat, difficulty swallowing, the feeling of food sticking in the throat, and a burning feeling in the chest. Causes of heartburn include dietary habits, lifestyle habits, and medical causes. Treatments for heartburn include lifestyle changes, OTC medication,prescription medication, and surgery.
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Why Am I So Gassy and Bloated?
Bloating is a feeling that your abdomen is distended or larger than normal, but it does not necessarily mean that it is. Gas (flatulence) also can be a problem if you are bloated. Common, less serious causes of bloating are eating too fast, too much, or too many fatty foods; swallowing air; pregnancy; and menstruation. Cancer and IBD (ulcerative colitis and Crohn's disease) are examples of the more serious causes of bloating. Examples of foods and drinks that cause bloating are high-fiber foods if you don't eat them regularly; eventually the bloating and gassiness will resolve if you eat them on a regular basis; fatty greasy foods, dairy products (for example, cheese, ice cream, milk, and yogurt); foods high in salt (for example, processed, frozen, and canned foods), and artificial sweeteners. Some doctors and other health care professionals recommend natural remedies like chamomile or peppermint tea or pumpkin to relieve bloating. Examples of OTC medicine (medicine available without a prescription) and other products that may relieve bloating and gassiness are, Gas-X, Beano, Pepto Bismol, Metamucil, probiotics, and Ex-Lax for constipation associated with bloating. If you have persistent or severe gas and bloating, and if you have any of these symptoms see a doctor or other health care professional, shortness of breath, heart palpitations, chest pain, bloody diarrhea, fever, or if you think you are or may be pregnant.
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Colic in Babies
Colic is crying or fussing that begins suddenly, lasting for a total of three hours a day and happening more than three days a week for about three weeks. Symptoms include the baby's face turning red, the belly is distended, the feet may be cold, the hands clenched, and the legs may alternate between being flexed or extended. Treatment may involve ruling out other causes of the fussing and the doctor prescribing anti-gas bubbly medicine.
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Heartburn During Pregnancy
Heartburn during pregnancy is quite common. During pregnancy the lower esophageal sphincter muscle becomes weakened , which likely occurs due to the effect of the high levels of the hormones estrogen and progesterone during pregnancy. Fortunately, this resolves after pregnancy. Management of heartburn during pregnancy are generally involves lifestyle changes and avoiding foods that promote heartburn, for example, don't smoke, avoid tight clothing, eat small, frequent meals, chew gum, or sip liquids.
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Prevention & Wellness
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Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Black R, Hill A. Over the counter medications in pregnancy. Am Fam Physician. 2003 Jun 15;67(12):2517-2524.