Fioricet is a combination of acetaminophen, butalbital, and caffeine. Acetaminophen is an analgesic, butalbital is a barbiturate, and caffeine is a stimulant. Acetaminophen stops the production of prostaglandins, which are chemicals that cause inflammation and pain. This action reduces pain signals sent to the brain. Fioricet is a prescription medication for treating tension headaches and migraines. It is also sometimes prescribed for other off-label uses, including post-traumatic headache and fibromyalgia, to help with sleep. It can also treat pain caused by tension headaches and muscle spasms. In addition, Fioricet may be used to reduce the number of headaches in individuals who suffer from chronic tension headaches. Additionally, Fioricet has been used to reduce the frequency and intensity of migraines.