ALKA-SELTZER ANTACID TABLETS 2PK 36PK/BX extended description: First Aid Only/Acme United Alka-Seltzer, 2/pk, Comparable to Tums and Maalox, these antacid tablets are used to relieve the discomfort of heartburn, sour stomach, and acid indigestion. Active ingredient: Calcium Carbonate 420 mg. 36 Packs/Box