Acetaminophen is a pain reliever and fever reducer. Butalbital is in a group of drugs called barbiturates. It relaxes muscle contractions involved in a tension headache. Caffeine is a central nervous system stimulant. It relaxes muscle contractions in blood vessels to improve blood flow. Acetaminophen, butalbital, and caffeine is a combination medicine used to treat… Continue reading Is it OK to donate blood if I take Fioricet (Butalbital APAP Caffeine)?