Alka seltzer original tablets can be used to treat conditions such as migraines period pains toothache sore throats joint swelling and stiffness neuralgia lower back pain sciatica rheumatic and muscular aches and pains muscle tenderness and stiffness sprains strains and symptoms of cold and flu such as feverishness being an antacid alka seltzer is especially useful for acid indigestion and heartburn helping to break up the full feeling and pain fast