Butalbital And Acetaminophen - Butalbital And Acetaminophen tablet prescribing information
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.
INDICATIONS AND USAGE
Butalbital and Acetaminophen Tablets are indicated for the relief of the symptom complex of tension (or muscle contraction) headache.
Evidence supporting the efficacy and safety of this combination product in the treatment of multiple recurrent headaches is unavailable. Caution in this regard is required because butalbital is habit-forming and potentially abusable.
DOSAGE AND ADMINISTRATION
Butalbital and Acetaminophen Tablets 50 mg/300 mg: One or two tablets every four hours. Total daily dosage should not exceed 6 tablets.
Extended and repeated use of these products is not recommended because of the potential for physical dependence.
CONTRAINDICATIONS
This product is contraindicated under the following conditions:
- Hypersensitivity or intolerance to any component of this product.
- Patients with porphyria.
ADVERSE REACTIONS
Frequently Observed: The most frequently reported adverse reactions are drowsiness, lightheadedness, dizziness, sedation, shortness of breath, nausea, vomiting, abdominal pain, and intoxicated feeling.
Infrequently Observed: All adverse events tabulated below are classified as infrequent.
Central Nervous: headache, shaky feeling, tingling, agitation, fainting, fatigue, heavy eyelids, high energy, hot spells, numbness, sluggishness, seizure. Mental confusion, excitement or depression can also occur due to intolerance, particularly in elderly or debilitated patients, or due to overdosage of butalbital.
Autonomic Nervous: dry mouth, hyperhidrosis.
Gastrointestinal: difficulty swallowing, heartburn, flatulence, constipation.
Cardiovascular: tachycardia.
Musculoskeletal: leg pain, muscle fatigue.
Genitourinary: diuresis.
Miscellaneous: pruritus, fever, earache, nasal congestion, tinnitus, euphoria, allergic reactions.
Several cases of dermatological reactions, including toxic epidermal necrolysis and erythema multiforme, have been reported.
The following adverse drug events may be borne in mind as potential effects of the components of this product. Potential effects of high dosage are listed in the OVERDOSAGE section.
Acetaminophen: allergic reactions, rash, thrombocytopenia, agranulocytosis.
To report SUSPECTED ADVERSE REACTIONS , contact Quagen Pharmaceuticals LLC at1-888-344-9603 or www.quagenpharma.com, or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Drug interactions
The CNS effects of butalbital may be enhanced by monoamine oxidase (MAO) inhibitors.
Butalbital and acetaminophen may enhance the effects of: other narcotic analgesics, alcohol, general anesthetics, tranquilizers such as chlordiazepoxide, sedative-hypnotics, or other CNS depressants, causing increased CNS depression.
DESCRIPTION
Each Butalbital and Acetaminophen Tablet for oral administration, contains Butalbital, USP 50 mg, Acetaminophen, USP 300 mg.
In addition, each Butalbital and Acetaminophen Tablet contains the following inactive ingredients: Colloidal Silicon Dioxide, Crospovidone, Croscarmellose Sodium, Povidone, Microcrystalline Cellulose, Pregelatinized Starch, D&C Yellow #10 Lake, FD&C Red #40 Lake and Stearic Acid.
Butalbital (5-allyl-5-isobutylbarbituric acid), a slightly bitter, white, odorless, crystalline powder, is a short to intermediate-acting barbiturate. It has the following structural formula:
MOLECULAR WEIGHT = 224.26
Acetaminophen (4'-hydroxyacetanilide), a slightly bitter, white, odorless, crystalline powder, is a non-opiate, non-salicylate analgesic and antipyretic. It has the following structural formula:
MOLECULAR WEIGHT = 151.16
CLINICAL PHARMACOLOGY
This combination drug product is intended as a treatment for tension headache.
It consists of a fixed combination of butalbital and acetaminophen. 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-dihydroxy-propyl) 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.
See OVERDOSAGE for toxicity information.
Acetaminophen: Acetaminophen is rapidly absorbed from the gastrointestinal tract and is distributed throughout most body tissues. The plasma half-life is 1.25 to 3 hours, but may be increased by liver damage and following overdosage. Elimination of acetaminophen is principally by liver metabolism (conjugation) and subsequent renal excretion of metabolites. 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.
See OVERDOSAGE for toxicity information.
HOW SUPPLIED
Yellow, round, biconvex unscored tablets debossed " T abov e 2 8 " on one side and plain on the other side, in bottles of 100 (NDC 70752-147-10) and bottles of 500 (NDC 70752-147-14). Each tablet contains butalbital, USP 50 mg and acetaminophen, USP 300 mg.
Store at 20°C to 25°C (68°F to 77°F) [see USP Controlled Room Temperature].
Dispense in a tight container as defined in the USP.
