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Mylanta Tonight

Generic name: calcium carbonate, magnesium hydroxide, and simethiconeKAL-see-um-KAR-boe-nate, mag-NEE-zee-um-hye-DROX-ide, and-sye-METH-i-kone ]
Brand names: Mylanta Coat & Cool, Mylanta Tonight
Drug class: Antacids

Medically reviewed by on Mar 30, 2023. Written by Cerner Multum.

What is Mylanta Tonight?

Calcium and magnesium are naturally occurring minerals that are sometimes used as antacids to relieve heartburn, acid indigestion, and upset stomach. Simethicone allows gas bubbles in the stomach and intestines to come together more easily.

Mylanta Tonight is a combination antacid, anti-gas medicine used to treat heartburn, indigestion, gas and bloating, or stomach discomfort caused by overeating.

Mylanta Tonight may also be used for purposes not listed in this medication guide.

Mylanta Tonight side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

Ask a doctor or pharmacist if this medicine is safe to use if you have ever had:

  • kidney disease; or

  • a condition for which you need to limit your intake of magnesium.

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

Do not give this medicine to a child younger than 12 years old without a doctor's advice.

How should I take Mylanta Tonight?

Use exactly as directed on the label, or as prescribed by your doctor.

Mylanta Tonight is usually taken between meals, at bedtime, or as directed by your doctor.

Shake the medicine before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Do not use this medicine for longer than 2 weeks, unless your doctor tells you to.

Call your doctor if your symptoms do not improve, or if they get worse.

Store at room temperature away from moisture and heat. Do not freeze.

What happens if I miss a dose?

Since Mylanta Tonight is used when needed, you may not be on a dosing schedule. Skip any missed dose if it's almost time for your next dose. Do not take more than 6 doses in a 24-hour period.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Mylanta Tonight?

Antacids can make it harder for your body to absorb other medicines you take by mouth. Avoid taking other medications at the same time you take Mylanta Tonight.

Ask a doctor or pharmacist before using over-the-counter stomach medicine or antacids that may contain ingredients similar to Mylanta Tonight.

What other drugs will affect Mylanta Tonight?

Some antacids can make it harder for your body to absorb certain drugs, making them less effective. Take your other medications at least 2 hours before or 2 hours after you take Mylanta Tonight.

Other drugs may affect Mylanta Tonight, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

More about Mylanta Tonight (calcium carbonate / magnesium hydroxide / simethicone)

Patient resources

Other brands

Mylanta Coat & Cool

Related treatment guides

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.