Alka seltzer xs contains aspirin paracetamol and caffeine for rapid relief of pain including migraine headache period pains neuralgia toothache sore throat symptomatic relief of rheumatic pain sciatica lumbago fibrositis muscular aches and pains symptomatic relief of influenza feverishness feverish coldsalka seltzer xs must always be dissolved in a glass of water prior to oral administration the dose in adults elderly and children aged 16 years and over is 2 tablets in water th