Instruct patients to look for acetaminophen or APAP on package labels and not to use more than one product that contains acetaminophen. The risk of acute liver failure is higher in individuals with underlying liver disease and in individuals who ingest alcohol while taking acetaminophen. The excessive intake of acetaminophen may be intentional to cause self-harm or unintentional as patients attempt to obtain more pain relief or unknowingly take other acetaminophen-containing products. Most of the cases of liver injury are associated with the use of acetaminophen at doses that exceed 4000 milligrams per day, and often involve more than one acetaminophen-containing product. – Hypersensitivity or intolerance to any component of this productĪcetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplant and death. Caution in this regard is required because butalbital is habit-forming and potentially abusable. INDICATIONS AND USAGEīutalbital, acetaminophen and caffeine tablets are indicated for the relief of the symptom complex of tension (or muscle contraction) headache.Įvidence supporting the efficacy and safety of this combination product in the treatment of multiple recurrent headaches is unavailable. Of the 70% of the dose that is recovered in the urine, only 3% is unchanged drug. Hepatic biotransformation prior to excretion results in about equal amounts of 1-methylxanthine and 1-methyluric acid. Like most xanthines, caffeine is rapidly absorbed and distributed in all body tissues and fluids, including the CNS, fetal tissues, and breast milk.Ĭaffeine is cleared through metabolism and excretion in the urine. Approximately 85% of an oral dose appears in the urine within 24 hours of administration, most as the glucuronide conjugate, with small amounts of other conjugates and unchanged drug. Elimination of acetaminophen is principally by liver metabolism (conjugation) and subsequent renal excretion of metabolites. The plasma half-life is 1.25 to 3 hours, but may be increased by liver damage and following overdosage. AcetaminophenĪcetaminophen is rapidly absorbed from the gastrointestinal tract and is distributed throughout most body tissues. The plasma-to-blood concentration ratio was almost unity, indicating that there is no preferential distribution of butalbital into either plasma or blood cells.

This falls within the range of plasma protein binding (20%–45%) reported with other barbiturates such as phenobarbital, pentobarbital, and secobarbital sodium. The in vitro plasma protein binding of butalbital is 45% over the concentration range of 0.5–20 mcg/mL. Of the material excreted in the urine, 32% is conjugated. Urinary excretion products include parent drug (about 3.6% of the dose), 5-isobutyl-5-(2, 3-dihydroxypropyl) barbituric acid (about 24% of the dose), 5-allyl-5(3-hydroxy-2-methyl-1-propyl) barbituric acid (about 4.8% of the dose), products with the barbituric acid ring hydrolyzed with excretion of urea (about 14% of the dose), as well as unidentified materials. They are bound to plasma and tissue proteins to a varying degree and binding increases directly as a function of lipid solubility.Įlimination of butalbital is primarily via the kidney (59% to 88% of the dose) as unchanged drug or metabolites. Barbiturates in general may appear in breast milk and readily cross the placental barrier. Butalbitalīutalbital is well absorbed from the gastrointestinal tract and is expected to distribute to most tissues in the body. The behavior of the individual components is described below. The role each component plays in the relief of the complex of symptoms known as tension headache is incompletely understood. It consists of a fixed combination of butalbital, acetaminophen and caffeine. This combination drug product is intended as a treatment for tension headache. (click image for full-size original) CLINICAL PHARMACOLOGY

Butalbital acetaminophen caffeine