Get fast relief of heartburn, upset stomach, and acid indigestion with headache or body aches. Alka-Seltzer has been around for more than 80 years. Unlike Tums or Mylanta, H-2 blockers such as Pepcid, and PPIs like Prilosec and Nexium, Alka-Seltzer® Original contains an analgesic for pain accompanied by heartburn and acid indigestion.