Fioricet is a combination medicine consisting of Acetaminophen, Caffeine, and Butalbital. You can conveniently Buy Fioricet Online. Fioricet is used to treat tension headaches and migraines. Acetaminophen helps decrease the pain from headache; caffeine helps increase the effects of acetaminophen; butalbital, a sedative, reduces anxiety and causes sleepiness and relaxation. Fioricet relaxes muscle contractions involved in a headache and improves blood flow.