Fioricet

Fioricet and Esgic are brand name drugs made from a combination of acetaminophen (325 mg), butalbital (a barbiturate, 50 mg), and caffeine (40 mg). They are indicated for the treatment of tension headaches and muscle contraction headaches. Although not indicated, they are commonly used to treat migraines and other pain related ailments.

Usage and Dosage
Fioricet is indicated for the treatment of complex and muscle contraction headaches. It is also commonly prescribed for migraines although it is not FDA indicated for this use. The usual adult dose is 1-2 tablets every four hours as needed, not exceeding six tablets in a 24 hour period.

Mechanism of action
Butalbital has generalized depressant effect on central nervous system and, in very high doses, has peripheral effects. Acetaminophen has analgesic and antipyretic effects; its analgesic effects may be mediated through inhibition of prostaglandin synthetase enzyme complex. Caffeine is thought to produce constriction of cerebral blood vessels.
Butalbital has half-life of about 35 hours. Acetaminophen half-life is 1.25 to 3 hours, but may be increased by liver damage and following overdosage. Caffeine half-life is about 3 hours.

Side effects
Side effects for any drug are difficult to predict, but commonly reported side effects for Fioricet include:
Abdominal pain
Dizziness
Drowsiness
Intoxicated feeling
Light-headedness
Nausea
Vomiting
Sedation
Addiction
Shortness of breath
Abdominal pain