Complete SPL Sections
DESCRIPTION
DESCRIPTION SECTION
Methocarbamol Tablets USP, 500 mg and 750 mg, a carbamate derivative of guaifenesin, is a central nervous system (CNS) depressant with sedative and musculoskeletal relaxant properties. The chemical name of methocar-bamol is 3-(2-methoxyphenoxy)-1, 2-propanediol 1-carbamate and has the empirical formula C H NO . Its molecular weight is 241.24. The structural formula is shown below. 11 15 5 Methocarbamol is a white powder, sparingly soluble in water and chloroform, soluble in alcohol (only with heating) and propylene glycol, and insoluble in benzene and -hexane. n Methocarbamol tablet, 500 mg is available as an orange, film coated, round convex tablet containing 500 mg of methocarbamol, USP for oral administration. The inactive ingredients present are microcrystalline cellulose, croscarmellose sodium, FD&C Yellow 6 aluminum lake, hydroxypropyl cellulose, hypromellose, magnesium stearate, polyethylene glycol, triacetin, titanium dioxide. Methocarbamol tablet, 750 mg is available as a yellow, film coated, modified capsule shaped tablet containing 750 mg of methocarbamol, USP for oral administration. The inactive ingredients present are microcrystalline cellulose, croscarmellose sodium, iron oxide yellow, iron oxide red, hydroxypropyl cellulose, hypromellose, magnesium stearate, polyethylene glycol, triacetin, titanium dioxide.
CLINICAL PHARMACOLOGY
CLINICAL PHARMACOLOGY SECTION
The mechanism of action of methocarbamol in humans has not been established, but may be due to general central nervous system (CNS) depression. It has no direct action on the contractile mechanism of striated muscle, the motor end plate or the nerve fiber.
Pharmacokinetics
PHARMACOKINETICS SECTION
In healthy volunteers, the plasma clearance of methocarbamol ranges between 0.20 and 0.80 L/h/kg, the mean plasma elimination half-life ranges between 1 and 2 hours, and the plasma protein binding ranges between 46% and 50%. Methocarbamol is metabolized via dealkylation and hydroxylation. Conjugation of methocarbamol also is likely. Essentially all methocarbamol metabolites are eliminated in the urine. Small amounts of unchanged methocarbamol also are excreted in the urine.
Special populations
SPL UNCLASSIFIED SECTION
Elderly
SPL UNCLASSIFIED SECTION
The mean (± SD) elimination half-life of methocarbamol in elderly healthy volunteers (mean (± SD) age, 69 (± 4) years) was slightly prolonged compared to a younger (mean (± SD) age, 53.3 (± 8.8) years), healthy population (1.5 (±0.4) hours versus 1.1 (± 0.27) hours, respectively). The fraction of bound methocarbamol was slightly decreased in the elderly versus younger volunteers (41 to 43% versus 46 to 50%, respectively).
Renally impaired
SPL UNCLASSIFIED SECTION
The clearance of methocarbamol in 8 renally-impaired patients on maintenance hemodialysis was reduced about 40% compared to 17 normal subjects, although the mean (± SD) elimination half-life in these two groups was similar: 1.2 (± 0.6) versus 1.1 (± 0.3) hours, respectively.
Hepatically impaired
SPL UNCLASSIFIED SECTION
In 8 patients with cirrhosis secondary to alcohol abuse, the mean total clearance of methocarbamol was reduced approximately 70% compared to that obtained in 8 age- and weight-matched normal subjects. The mean (± SD) elimination half-life in the cirrhotic patients and the normal subjects was 3.38 (±1.62) hours and 1.11 (± 0.27) hours, respectively. The percent of methocarbamol bound to plasma proteins was decreased to approximately 40 to 45% compared to 46 to 50% in the normal subjects.
INDICATIONS AND USAGE
INDICATIONS & USAGE SECTION
Methocarbamol is indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomfort associated with acute, painful musculoskeletal conditions. The mode of action of methocarbamol has not been clearly identified, but may be related to its sedative properties. Methocarbamol does not directly relax tense skeletal muscles in man.
CONTRAINDICATIONS
CONTRAINDICATIONS SECTION
Methocarbamol is contraindicated in patients hypersensitive to methocarbamol or to any of the tablet components.
WARNINGS
WARNINGS SECTION
Since methocarbamol may possess a general CNS depressant effect, patients receiving methocarbamol tablets should be cautioned about combined effects with alcohol and other CNS depressants. Safe use of methocarbamol has not been established with regard to possible adverse effects upon fetal development. There have been reports of fetal and congenital abnormalities following in utero exposure to methocarbamol. Therefore, methocarbamol tablets should not be used in women who are or may become pregnant and particularly during early pregnancy unless in the judgment of the physician the potential benefits outweigh the possible hazards (see ). PRECAUTIONS, Pregnancy
PRECAUTIONS
PRECAUTIONS SECTION
ADVERSE REACTIONS
ADVERSE REACTIONS SECTION
Adverse reactions reported coincident with the administration of methocarbamol include:
OVERDOSAGE
OVERDOSAGE SECTION
Limited information is available on the acute toxicity of methocarbamol. Overdose of methocarbamol is frequently in conjunction with alcohol or other CNS depressants and includes the following symptoms: nausea, drowsiness, blurred vision, hypotension, seizures, and coma. In post-marketing experience, deaths have been reported with an overdose of methocarbamol alone or in the presence of other CNS depressants, alcohol or psychotropic drugs.
DOSAGE AND ADMINISTRATION
DOSAGE & ADMINISTRATION SECTION
Methocarbamol, 500 mg – Adults: Initial dosage: 3 tablets q.i.d. Maintenance dosage: 2 tablets q.i.d. Methocarbamol, 750 mg – Adults: Initial dosage: 2 tablets q.i.d. Maintenance dosage: 1 tablet q.4h. or 2 tablets t.i.d. Six grams a day are recommended for the first 48 to 72 hours of treatment. (For severe conditions 8 grams a day may be administered). Thereafter, the dosage can usually be reduced to approximately 4 grams a day.
HOW SUPPLIED
HOW SUPPLIED SECTION
Product: 68151-2775 NDC: 68151-2775-7 1 TABLET, FILM COATED in a BOTTLE
SPL UNCLASSIFIED SECTION
SPL UNCLASSIFIED SECTION
LBL112 REV082713 Revised: August 2013 Manufactured for: AustarPharma LLC 18 Mayfield Ave, Edison, NJ 08837, USA By Hangzhou Minsheng Binjiang Pharmaceutical Co., Ltd. Hangzhou, 310051, China Distributed by: Virtus Pharmaceuticals LLC 2649 Causeway Center Dr. Tampa, FL 33619, USA 1-813-283-1344
METHOCARBAMOL TABLET, FILM COATED
PACKAGE LABEL.PRINCIPAL DISPLAY PANEL