ESGIC- butalbital, acetaminophen and caffeine tablet
Forest Laboratories, Inc.
WARNING
HEPATOTOXICITY
ACETAMINOPHEN HAS BEEN ASSOCIATED WITH CASES OF ACUTE LIVER FAILURE, AT TIMES RESULTING IN LIVER TRANSPLANT AND DEATH. 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.
DESCRIPTION
Butalbital, acetaminophen and caffeine are supplied in tablet form for oral administration.
Each Tablet contains the following active ingredients:
Butalbital ������.50 mg
Warning: May be habit-forming.
Acetaminophen ���.325 mg
Caffeine �������.40 mg
In addition, each tablet contains the following inactive ingredients: colloidal silicon dioxide, croscarmellose sodium, crospovidone, microcrystalline cellulose, povidone, pregelatinized corn starch and stearic acid.
Butalbital (5-allyl-5-isobutylbarbituric acid) is a short to intermediate-acting barbiturate. It has the following structural formula:
butalbital chemical structure
C11 H16 N2 O3 MW = 224.26
Acetaminophen (4?-hydroxyacetanilide) is a non-opiate, non-salicylate analgesic and antipyretic. It has the following structural formula:
acetaminophen chemical structure
C8 H9 NO2 MW = 151.16
Caffeine (1,3,7-trimethylxanthine) is a central nervous system stimulant. It has the following structural formula:
caffeine chemical structure
C8 H10 N4 O2 MW = 194.19
CLINICAL PHARMACOLOGY
This combination drug product is intended as a treatment for tension headache.
It consists of a fixed combination of butalbital, acetaminophen and caffeine. The role each component plays in the relief of the complex of symptoms known as tension headache is incompletely understood.
Pharmacokinetics
The behavior of the individual components is described below.
Butalbital: Butalbital is well absorbed from the gastrointestinal tract and is expected to distribute to most tissues in the body. Barbiturates in general may appear in breast milk and readily cross the placental barrier. They are bound to plasma and tissue proteins to a varying degree and binding increases directly as a function of lipid solubility.
Elimination of butalbital is primarily via the kidney (59% to 88% of the dose) as unchanged drug or metabolites. The plasma half-life is about 35 hours. 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. Of the material excreted in the urine, 32% is conjugated.
