Generic name: acetaminophen / butalbital / caffeine / codeine
Phrenilin with Caffeine and Codeine is used to relieve tension headaches. It may also be used by your physician to treat certain other conditions.
The medicine refers to stimulant, analgesic, barbiturate, and narcotic combination. Acetaminophen and codeine relieve pain. Caffeine constricts blood vessels, which cause headaches. Butalbital works by reducing anxiety and promoting relaxation.