Alka-Seltzer Original Effervescent Tablets Alka-Seltzer Original Effervescent Tablets provide fast, effective pain relief from mild to moderate pain such as headache, migraine, back-ache (including lumbago), nerve pain (neuralgia & sciatica), period pain, toothache & sore throat. They also provide symptomatic relief from colds & influenza & from rheumatic pain (arthritis), muscle tenderness & stiffness (including fibrositis), muscular aches & pains, the pain of joint swelling & stiffness, strains & sprains. If you have a high temperature, Alka Seltzer Original Effervescent Tablets will effectively reduce this too. The main ingredient in Alka-Seltzer Original Effervescent Tablets is aspirin, which belongs to a group of medicines known as non-steroidal anti-inflammatory drugs (NSAIDs). It treats pain, reduces fever & also has anti-inflammatory properties. The other ingredients are sodium hydrogen carbonate & citric acid which help to create a sparkling solution.