What is Antacid: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

Antacid overview

BRAND NAMES:

  • Advacal, Alcalak, Alka-Mints, Alka-Seltzer Heartburn Relief, Alka-Seltzer Heartburn ReliefChews, Antacid, Antacid Ultra Strength, Ban-acid, Cal-C-Caps, Cal-Cee, Calcium Antacid, Cal-G, Cal-Lac, Cal-Gest, Cal-Mint, Acid Gone, Almacone, Almacone Double Strength, Alumina-Magnesia-Simethicone, Antacid, Antacid and Gas Relief, Antacid Anti-Gas, Antacid-Antigas, Antacid Extra Strength, Antacid Liquid, Antacid w/Simethicone, Equaline Antacid, Equate Antacid, Gavis-Care, Gaviscon ESRF, Almacone, Almacone Double Strength, Alumina-Magnesia-Simethicone, Antacid, Antacid and Gas Relief, Antacid Anti-Gas, Antacid Extra Strength, Antacid Liquid, Antacid-Antigas, Gelusil, Geri-Lanta, Geri-Mox, Equate Antacid, Equaline Antacid, Antacid w/Simethicone, Alka-Mints, Alka-Seltzer Heartburn+Gas, Alka-Seltzer Heartburn Relief, Alka-Seltzer Heartburn ReliefChews, Antacid, Antacid Ultra Strength, Ban-acid, Calcium Antacid, Calcium Antacid Extra Strength, Cal-Gest, Caltrate 600, Children's Pepto, Family Pharmacy Calcium 500, Gas-X with Maalox, Good Neighbor Pharmacy Antacid

Generic Names:

  • Calcium Carbonate Antacid

Uses:

  • Treats indigestion, gas, heartburn, peptic ulcers, and other conditions., Treats indigestion, gas, heartburn, peptic ulcers, and other digestive problems., Treats upset stomach, heartburn, and gas., Supplies your body with calcium if you need more than you get in your diet. Also helps prevent osteoporosis (weak or brittle bones). This medicine is a mineral that your body needs to work properly.

Therapeutic Classes:

  • Antacid, Antacid, Calcium Containing, Antidote, Calcium Supplement, Nutriceutical, Phosphate Binder, Antacid, Aluminum/Magnesium Containing, Antacid, Aluminum Containing, Antacid, Magnesium Containing, Antidote, Antacid, Aluminum/Magnesium Containing, Antacid, Aluminum Containing, Antacid, Magnesium Containing, Antacid, Magnesium Containing, Antiflatulent, Calcium Supplement, Antacid, Aluminum/Calcium/Magnesium Containing, Antacid, Aluminum Containing, Antacid, Calcium Containing

Forms:

  • Liquid, Powder for Suspension, Tablet, Capsule, Chewable Tablet, Lozenge, Wafer, Long Acting Tablet, Tablet, Chewable Tablet, Liquid, Capsule, Liquid, Tablet, Capsule, Chewable Tablet, Tablet, Chewable Tablet, Liquid, Wafer, Liquid Filled Capsule, Capsule, Granule, Powder

How it’s taken:

  • By mouth, By mouth, By mouth, By mouth

What is Antacid used for?

What form(s) does Antacid come in

  • Liquid

  • Powder for Suspension

  • Tablet

  • Capsule

  • Chewable Tablet

  • Lozenge

  • Wafer

  • Long Acting Tablet

  • Tablet

  • Chewable Tablet

  • Liquid

  • Capsule

  • Liquid

  • Tablet

  • Capsule

  • Chewable Tablet

  • Tablet

  • Chewable Tablet

  • Liquid

  • Wafer

  • Liquid Filled Capsule

  • Capsule

  • Granule

  • Powder

What are common Antacid doses?

  • Bottle 150 Tablets Chewable

How to take Antacid

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Follow the instructions on the medicine label if you are using this medicine without a prescription. Ask your pharmacist or health caregiver if you are not sure how much calcium you should take in one day.

  • Most calcium supplements should be taken with food. Drink a full glass of water (8 ounces) with each dose, unless you are on kidney dialysis. If you are using this medicine as a phosphate binder for kidney dialysis, do not drink extra water with each dose.

  • Oral routeCarefully follow your doctor's instructions about any special diet.

  • If you need to take more than one dose each a day, take each dose at evenly spaced times, unless your doctor has told you otherwise.

  • Do not crush, break, or chew the tablet or capsule unless the label says it is chewable. Swallow the regular tablet or capsule whole.

  • If you are using the chewable tablet or wafer, chew it completely before you swallow.

  • Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup. You might need to shake the medicine just before using it.

  • Follow the instructions on the medicine label if you are using this medicine without a prescription. Ask your pharmacist or health caregiver if you are not sure how much calcium you should take in one day.

  • If you need to take more than one dose each a day, take each dose at evenly spaced times, unless your doctor has told you otherwise.

  • Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup. You might need to shake the medicine just before using it.

  • Oral routeCarefully follow your doctor's instructions about any special diet.

  • If you are using the chewable tablet or wafer, chew it completely before you swallow.

  • Most calcium supplements should be taken with food. Drink a full glass of water (8 ounces) with each dose, unless you are on kidney dialysis. If you are using this medicine as a phosphate binder for kidney dialysis, do not drink extra water with each dose.

  • Do not crush, break, or chew the tablet or capsule unless the label says it is chewable. Swallow the regular tablet or capsule whole.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Follow the instructions on the medicine label if you are using this medicine without a prescription.

  • Liquid: Shake well just before you measure a dose. Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.

  • Chewable tablet: Do not swallow whole. Chew thoroughly before you swallow.

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Do not freeze.

  • Follow the instructions on the medicine label if you are using this medicine without a prescription.

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Do not freeze.

  • Chewable tablet: Do not swallow whole. Chew thoroughly before you swallow.

  • Liquid: Shake well just before you measure a dose. Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Follow the instructions on the medicine label if you are using this medicine without a prescription.

  • If you are being treated for peptic ulcer, keep using this medicine for as long as your doctor tells you to.

  • Shake the oral liquid just before using. Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.

  • Chew the chewable tablet before swallowing. Do not swallow whole.

  • Shake the oral liquid just before using. Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.

  • Chew the chewable tablet before swallowing. Do not swallow whole.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Follow the instructions on the medicine label if you are using this medicine without a prescription.

  • If you are being treated for peptic ulcer, keep using this medicine for as long as your doctor tells you to.

  • Your doctor will tell you how much to use and how often. If you are being treated for peptic ulcer, keep using this medicine for as long as your doctor tells you to.

  • Follow the instructions on the medicine label if you are using this medicine without a prescription.

  • Shake the oral liquid well before each use. Measure your dose carefully using a measuring spoon or medicine cup.

  • Chew the chewable tablet thoroughly before swallowing. It may be helpful to drink a glass of water after swallowing the chewed tablet.

  • Let the lozenge melt slowly in your mouth.

  • Swallow the extended-release tablet whole. Do not crush, break, or chew it.

  • Oral routeCarefully follow your doctor's instructions about any special diet.

  • Chew the chewable tablet thoroughly before swallowing. It may be helpful to drink a glass of water after swallowing the chewed tablet.

  • Let the lozenge melt slowly in your mouth.

  • Swallow the extended-release tablet whole. Do not crush, break, or chew it.

  • Your doctor will tell you how much to use and how often. If you are being treated for peptic ulcer, keep using this medicine for as long as your doctor tells you to.

  • Follow the instructions on the medicine label if you are using this medicine without a prescription.

  • Shake the oral liquid well before each use. Measure your dose carefully using a measuring spoon or medicine cup.

  • Oral routeCarefully follow your doctor's instructions about any special diet.

What to do if you miss a dose of Antacid

  • If you use this medicine on a regular schedule, use the missed dose as soon as possible, unless it is almost time for your next dose.

  • Skip the missed dose if it is almost time for your next regular dose.

  • You should not use two doses at the same time.

  • Take the missed dose as soon as possible.

  • If it is almost time for your next regular dose, wait until then take the medicine and skip the missed dose.

  • You should not use two doses at the same time.

  • Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Antacid contraindications

  • You should not use this medicine if you have had an allergic reaction to calcium.

  • This medicine is not right for everyone. Do not use it if you had an allergic reaction to simethicone, aluminum, or magnesium.

  • You should not use this medicine if you have had an allergic reaction to medicines that contain aluminum, magnesium, or simethicone.

  • You should not use this medicine if you have had an allergic reaction to medicines that contain calcium. Make sure your doctor knows if you have had hypercalcemia (too much calcium in your body).

Antacid warnings

  • If you are using a large amount of calcium or using it for a long time, your doctor might need to check your blood on a regular basis. Be sure to keep all appointments.

  • Some health problems can affect how much calcium you should take. Tell your doctor if you have stomach or digestion problems, such as on-going diarrhea, not absorbing nutrients properly, or not having enough acid in your stomach.

  • You should not use certain brands of this medicine if you have kidney disease or are on dialysis, because they may harm your kidneys. Ask your caregiver what brands are best for you.

  • Make sure your doctor knows if you are pregnant or breast feeding, or if you are allergic to shellfish. Tell your doctor if you have kidney disease or have ever had kidney stones. Make sure your doctor knows if you have had problems with too much calcium (hypercalcemia) or too little calcium in your blood (hypocalcemia). Some health problems that can cause hypercalcemia are sarcoidosis or problems with your parathyroid gland.

  • Antacids may contain large amounts of salt. Talk to your doctor before taking this medicine if you are on a low-sodium (low-salt) diet.

  • If you are pregnant or breastfeeding, talk to your doctor before using this medicine.

  • Make sure your doctor knows if you have kidney disease or liver disease.

  • You should not use certain brands of this medicine if you have kidney disease or are on dialysis, because they may harm your kidneys. Ask your caregiver what brands are best for you.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

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

  • Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease.

  • You should not use certain brands of this medicine if you have kidney disease or are on dialysis, because they may harm your kidneys. Ask your caregiver what brands are best for you.

  • Tell your doctor if your heartburn or stomach problems do not get better after 1 or 2 weeks or if they get worse after taking this medicine.

  • If you are pregnant or breastfeeding, talk to your doctor before using this medicine.

  • Talk with your doctor before using antacids if you have kidney disease or liver disease.

  • Antacids may contain large amounts of salt. Talk to your doctor before using this medicine if you are on a low-sodium diet.

Antacid interactions

  • Antacids may keep other medicines from working the way they are supposed to. Do not use an antacid within 1 to 2 hours before or after using other medicines. If you have questions about when are the best times to use your medicines, ask your doctor or pharmacist.

  • If you are using an antibiotic such as tetracycline, minocycline, or doxycycline, do not take an antacid within 3 hours before or after taking the antibiotic.

  • Avoid drinking large amounts of milk with this medicine.

  • Tell your doctor if your heartburn or stomach problems do not get better after 1 or 2 weeks or if they get worse after taking this medicine.

  • Antacids may contain large amounts of salt. Talk to your doctor before using this medicine if you are on a low-sodium diet.

  • Talk with your doctor before you use this medicine if you are on a low-salt or low-magnesium diet.

  • Antacids affect how your body absorbs other medicines. You might need to take this antacid at a different time than your other medicines. Ask your pharmacist if you have questions.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

  • You should not use antacids within 1 to 2 hours before or after using other medicines.

  • If you are using this medicine for an ulcer, be sure to follow any diet instructions given to you by your doctor.

  • You should not use certain brands of this medicine if you have kidney disease or are on dialysis, because they may harm your kidneys. Ask your caregiver what brands are best for you.

  • Antacids may contain large amounts of salt. Talk to your doctor before taking this medicine if you are on a low-sodium (low-salt) diet.

  • Make sure your doctor knows if you are also using other supplements or medicines that contain calcium. Tell your doctor if you are also using gallium nitrate (Ganite®), cellulose sodium phosphate (Calcibind®), or etidronate (Didronel®).

  • Calcium can change the way other medicines work if you take them at the same time. If you need to use other medicines, take them at least 2 hours before or 2 hours after you take your calcium supplement. This is particularly important if you are also using phenytoin (Dilantin®) or a tetracycline antibiotic to treat an infection (such as doxycycline, minocycline, Vibramycin®).

  • Do not take your calcium supplement with a high-fiber meal (such as bran, whole-grain cereal or bread, fresh fruits). Do not smoke cigarettes or cigars. Do not drink large amounts of alcohol or caffeine (for example, more than about 8 cups of coffee).

  • If you are using a large amount of calcium or using it for a long time, your doctor might need to check your blood on a regular basis. Be sure to keep all appointments.

Antacid side effects

Serious Side Effects

  • Severe stomach pain, vomiting

  • Muscle pain or severe weakness

  • White-colored stools

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

  • Irregular heartbeat

  • Excessive weakness or tiredness

  • Severe stomach pain

  • White colored stools

  • Headache that will not go away, dry mouth, loss of appetite, severe constipation.

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

Less Serious Side Effects

  • Mild constipation, gas.

  • White colored stools

  • Constipation

  • Diarrhea

  • Unpleasant or chalky taste

  • Unpleasant or chalky taste

  • White-colored stools

  • Diarrhea

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