Antacids that contain calcium carbonate or aluminum dissolve more slowly and can take up to 30 minutes to begin working. The longer an antacid stays in the stomach, the longer it works. Those that contain calcium carbonate or aluminum work longer than those that contain sodium bicarbonate or magnesium. Also, taking any kind of antacid after a meal, instead of on an empty stomach, provides longer-lasting relief because the medicine stays in the stomach longer. Among the brands of antacid products on the market are Alka-Seltzer, Maalox, Mylanta, Tums, and Rolaids.
Generic forms are also available.
The dose depends on the type of antacid. Read and follow the directions on the package label. For questions about dosage, check with a physician or pharmacist. When using antacids in chewable tablet form, chew the tablet well before swallowing. Drink a glass of water after taking chewable aluminum hydroxide.