Drug Reference

Methocarbamol

Carbamic acid esters

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Rx only

Fact box

Therapeutic class
Carbamic acid esters
Action class
Muscle Relaxant
Habit forming
No
Availability
Prescription (Rx)

Brand names

AtmeksiRobaxinTanlor

Available as

500 MG · Oral Tablet750 MG · Oral Tablet325 MG · Oral Tablet10 ML · Injection1000 MG · Oral Tablet150 MG/ML · Oral Suspension

FDA label sections are from openFDA and may not reflect the most recent labeling — confirm against the current DailyMed label.

Uses
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.
How it works
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.
How to use / dosing
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.
Side effects
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

Safety advice

Conservative summary derived from FDA labeling — defaults to “consult your doctor” unless the label is explicit. Not a substitute for your clinician’s advice.

PregnancyUnsafe
Pregnancy Teratogenic effects Pregnancy Category C Animal reproduction studies have not been conducted with methocarbamol. It is also not known whether methocarbamol can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Methocarbamol tablets, USP should be given to a pregnant woman only if clearly needed. Safe use of Methocarbamol tablets, USP 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, USP 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 Warnings ). Nursing mothers Methocarbamol and/or its metabolites are excreted in the milk of dogs; however, it is not known whether methocarbamol or its metabolites are excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Methocarbamol tablets, USP are administered to a nursing woman. Pediatric use Safety and effectiveness of Methocarbamol tablets, USP in pediatric patients below the age of 16 have not been established.
BreastfeedingCaution
Nursing mothers Methocarbamol and/or its metabolites are excreted in the milk of dogs; however, it is not known whether methocarbamol or its metabolites are excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Methocarbamol tablets, USP are administered to a nursing woman.
Breastfeeding details — LactMed (NLM) →
AlcoholConsult your doctor
…tablets, USP should be cautioned about combined effects with alcohol and other CNS depressants.…
DrivingConsult your doctor
…abilities required for performance of hazardous tasks, such as operating machinery or driving a motor vehicle.…
KidneyNo information
No specific information in the FDA label.
LiverNo information
No specific information in the FDA label.
Warnings & precautions
WARNINGS Since methocarbamol may possess a general CNS depressant effect, patients receiving Methocarbamol tablets, USP should be cautioned about combined effects with alcohol and other CNS depressants. Safe use of Methocarbamol tablets, USP 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, USP 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 ). Use In Activities Requiring Mental Alertness Methocarbamol may impair mental and/or physical abilities required for performance of hazardous tasks, such as operating machinery or driving a motor vehicle. Patients should be cautioned about operating machinery, including automobiles, until they are reasonably certain that methocarbamol therapy does not adversely affect their ability to engage in such activities.
Contraindications
CONTRAINDICATIONS Methocarbamol tablets, USP are contraindicated in patients hypersensitive to methocarbamol or to any of the tablet components.

Pediatric use

Pediatric use Safety and effectiveness of Methocarbamol tablets, USP in pediatric patients below the age of 16 have not been established.

⚑ About half of pediatric medication use is off-label and not described in FDA labels — absence of pediatric information does not mean a medicine is unused or unsafe in children. Confirm with your clinician.

Interactions (label text — not an interaction checker)
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.
Overdose
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.
Current FDA labels (DailyMed)

11 marketed products on record (RxNorm)

Authoritative sources

Reference only — not clinical advice. Verify against current FDA labeling and consult a licensed provider. About half of pediatric drug use is off-label and is not reflected in FDA labels; absence of pediatric information does not mean a medicine is unused or unsafe in children.