Alka Seltzer XS Effervescent TabletsAlka-Seltzer XS Effervescent Tablets are a double action pain reliever for mild to moderate pain such as headache, migraine, backache (including lumbago), nerve pain (neuralgia and sciatica), period pain, toothache and sore throat. They also provide symptomatic relief from colds and influenza and from rheumatic pain (arthritis), muscle tenderness and stiffness (including fibrositis), muscular aches and pains, the pain of joint swelling and stiffness, strains and sprains. If you have a high temperature, Alka Seltzer XS Effervescent Tablets will effectively reduce this too.The main ingredients in Alka-Seltzer XS Effervescent Tablets are aspirin, which belongs to a group of medicines known as non-steroidal anti-inflammatory drugs (NSAIDs) and paracetamol. Aspirin and parcetamol both treat and pain and reduce fever, while aspirin is also an anti-inflammatory. They also contain caffeine which acts as a mild stimulant and sodium hydrogen carbonate and citric acid which help to create a sparkling solution.