Methocarbamol Tablets, USP, 500 mg

INDICATIONS AND USAGE Methocarbamol Tablets, USP are 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.

DOSAGE AND ADMINISTRATION Methocarbamol Tablets, USP, 500 mg – Adults: Initial dosage: 3 tablets four times daily Maintenance dosage: 2 tablets four times daily Methocarbamol Tablets, USP, 750 mg – Adults: Initial dosage: 2 tablets four times daily Maintenance dosage: 1 tablet every 4 hours or 2 tablets three times daily 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.

CONTRAINDICATIONS Methocarbamol Tablets, USP are contraindicated in patients hypersensitive to methocarbamol or to any of the tablet components.

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

Drug Interactions See WARNINGS and PRECAUTIONS for interaction with CNS drugs and alcohol. Methocarbamol may inhibit the effect of pyridostigmine bromide. Therefore, methocarbamol should be used with caution in patients with myasthenia gravis receiving anticholinesterase agents.

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 are available as a white, round, scored, film-coated tablet containing 500 mg of methocarbamol, USP for oral administration. The inactive ingredients present are microcrystalline cellulose, croscarmellose sodium, povidone (k-30), sodium lauryl sulfate, colloidal silicon dioxide, magnesium stearate, hypromellose, titanium dioxide, polyethylene glycol, polysorbate 80. Methocarbamol Tablets, USP 750 mg are available as a white, capsule-shaped, film-coated tablet containing 750 mg of methocarbamol, USP for oral administration. The inactive ingredients present are microcrystalline cellulose, croscarmellose sodium, povidone (k-30), sodium lauryl sulfate, colloidal silicon dioxide, magnesium stearate, hypromellose, titanium dioxide, polyethylene glycol, polysorbate 80. Methocarbamol structural formula

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.

HOW SUPPLIED Methocarbamol Tablets, USP, 500 mg tablets are white, round, film-coated tablets, debossed “G173” on one side, plain and scored on the other side. They are supplied as follows: Bottles of 100 NDC 10135-0722-01 Bottles of 500 NDC 10135-0722-05 Methocarbamol Tablets, USP, 750 mg tablets are white, capsule-shaped, film-coated tablets, debossed “G174” on one side and plain on the other side. They are supplied as follows: Bottles of 100 NDC 10135-0723-01 Bottles of 500 NDC 10135-0723-05 Store at 20o to 25o C (68o to 77o F) [see USP Controlled Room Temperature]. For 100 count, Dispense contents in a tight container with child-resistant closure. For 500 count, Dispense contents in a tight container.