Methocarbamol

Adverse Reactions Section ADVERSE REACTIONS Adverse reactions reported coincident with the administration of methocarbamol include: Body as a whole: Anaphylactic reaction, angioneurotic edema, fever, headache Cardiovascular system: Bradycardia, flushing, hypotension, syncope, thrombophlebitis Digestive system: Dyspepsia, jaundice (including cholestatic jaundice), nausea and vomiting Hemic and lymphatic system: Leukopenia Immune system: Hypersensitivity reactions Nervous system: Amnesia, confusion, diplopia, dizziness or lightheadedness, drowsiness, insomnia, mild muscular incoordination, nystagmus, sedation, seizures (including grand mal), vertigo Skin and special senses: Blurred vision, conjunctivitis, nasal congestion, metallic taste, pruritus, rash, urticaria.

Contraindications CONTRAINDICATIONS Methocarbamol Tablets USP, 500 mg and 750 mg are contraindicated in patients hypersensitive to methocarbamol or to any of the tablet components.

Description Methocarbamol Tablets USP, a carbamate derivative of guaifenesin, is a central nervous system (CNS) depressant with sedative and musculoskeletal relaxant properties. The chemical name of methocarbamol is 3 - (2-methoxyphenoxy) -1, 2- propanediol 1-carbamate and has the empirical formula C11H15NO5. Its molecular weight is 241.24. The structural formula is shown below. 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 n-hexane. Methocarbamol Tablets USP, 500 mg is available as a light orange colored, round, film-coated tablets, engraved with 'B134' on one side and scored on the other side, containing 500 mg of methocarbamol, USP for oral administration. The inactive ingredients present are corn starch, low substituted hydroxypropyl cellulose, hydroxyprolyl cellulose, sodium starch glycolate, povidone, sodium lauryl sulfate, colloidal silicon dioxide, stearic acid, magnesium stearate, and purified water. Methocarbamol Tablets USP, 500 mg contains Opadry 13H530000 (Orange) (hypromellose, titanium dioxide, propylene glycol, FD&C yellow #6/Sunset Yellow FCF Aluminum Lake, polysorbate 20) as coating material. Methocarbamol Tablets USP, 750 mg is available as an orange colored, capsule shaped, film coated tablets, engraved with 'B135' on one side and plain on the other side, containing 750 mg of methocarbamol, USP for oral administration. It contains Opadry 13H530001 (Orange) as coating material. The inactive ingredients present are corn starch, low substituted hydroxypropyl cellulose, hydroxyprolyl cellulose, sodium starch glycolate, povidone, sodium lauryl sulfate, colloidal silicon dioxide, stearic acid, magnesium stearate, and purified water. Methocarbamol Tablets USP, 750 mg contain Opadry 13H530001 (Orange) (hypromellose, titanium dioxide, propylene glycol, D&C Yellow #10 Aluminum Lake, FD&C yellow #6/Sunset Yellow FCC Aluminum Lake, polysorbate 20) as coating material. Structure

Dosage and Administration Section DOSAGE AND ADMINISTRATION Methocarbamol Tablets USP, 500 mg – Adults: Initial dosage: 3 tablets q.i.d. Maintenance dosage: 2 tablets q.i.d. Methocarbamol Tablets USP, 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.

Overdosage Section OVERDOSAGE 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. Treatment Management of overdose includes symptomatic and supportive treatment. Supportive measures include maintenance of an adequate airway, monitoring urinary output and vital signs, and administration of intravenous fluids if necessary. The usefulness of hemodialysis in managing overdose is unknown.

Clinical Pharmacology 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 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 Elderly 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 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 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.

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Methocarbamol Methocarbamol METHOCARBAMOL METHOCARBAMOL B135

ANDA208507

Methocarbamol

Methocarbamol

80425-0171

HUMAN PRESCRIPTION DRUG

ORAL

Principal Display Panel label 1 label 2 label 3

How Supplied/Storage and Handling Methocarbamol Tablets USP, 750 mg are orange colored, capsule shaped, film coated tablets, engraved with 'B135' on one side and plain on the other side. They are supplied as follows: Bottles of 30 tablets NDC 80425-0171-01 Bottles of 60 tablets NDC 80425-0171-02 Bottles of 90 tablets NDC 80425-0171-03 Store at controlled room temperature, between 20°C and 25°C (68°F and 77°F). Dispense in tight container. Manufactured for Beximco Pharmaceuticals USA Inc. 4110 Regal Oaks Drive, P.O. Box 1060 Suwanee, GA 30024, USA Manufactured by BEXIMCO PHARMACEUTICALS LTD. 126, Kathaldia, Tongi, Gazipur, 1711, Bangladesh Distributed by: Bayshore Pharmaceuticals LLC Short Hills, NJ 07078 Distributed by: Advanced Rx Pharmacy of Tennessee LLC, Nashville, TN 37211 Last revised on 12/2017 5001397 111217