Fioricet is a prescription medication used to relieve tension headaches. It is a combination of acetaminophen, butalbital, and caffeine. Acetaminophen is a pain reliever and fever reducer. Butalbital is a barbiturate that relaxes muscles. Caffeine is a stimulant that helps to relieve fatigue. Fioricet is available in tablet and capsule form. It is usually taken every 4 to 6 hours as needed for pain relief. Fioricet should not be taken for more than 10 days in a row without talking to a doctor. Fioricet can be habit-forming. Do not take more Fioricet than prescribed by your doctor. Taking too much Fioricet can lead to serious side effects, including overdose and death.