Robaxin 500 MG Oral Tablet
WARNINGS
Since methocarbamol may possess a general CNS depressant effect, patients receiving robaxin ® or robaxin ® -750 should be cautioned about combined effects with alcohol and other CNS depressants.
Safe use of robaxin ® and robaxin ® -750 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, robaxin ® and robaxin ® -750 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.
DRUG INTERACTIONS
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.
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.
DESCRIPTION
robaxin ® /robaxin ® -750 (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 C 11 H 15 NO 5 .
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.
robaxin ® is available as a light orange, round, film-coated tablet containing 500 mg of methocarbamol, USP for oral administration.
The inactive ingredients present are corn starch, FD&C Yellow 6, hydroxypropyl cellulose, hypromellose, magnesium stearate, polysorbate 20, povidone, propylene glycol, saccharin sodium, sodium lauryl sulfate, sodium starch glycolate, stearic acid, titanium dioxide.
robaxin ® -750 is available as an orange capsule-shaped, film-coated tablet containing 750 mg of methocarbamol, USP for oral administration.
In addition to the inactive ingredients present in robaxin ® , robaxin ® -750 also contains D&C Yellow 10.
Robaxin structural formula
HOW SUPPLIED
robaxin ® (methocarbamol tablets, USP) 500-mg tablets are light orange, round, film-coated tablets engraved with ROBAXIN 500 on the unscored side and SP above the score on the other side.
They are supplied as follows: Bottles of 100 NDC 52244-429-10 robaxin ® -750 (methocarbamol tablets, USP) 750-mg tablets are orange, capsule-shaped, film-coated tablets engraved with ROBAXIN 750 on one side and SP on the other.
They are supplied as follows: Bottles of 100 NDC 52244-449-10 Store at controlled room temperature, between 20°C and 25°C (68°F and 77°F).
Dispense in tight container.
INDICATIONS AND USAGE
robaxin ® and robaxin ® -750 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.
PEDIATRIC USE
Pediatric Use Safety and effectiveness of robaxin ® and robaxin ® -750 in pediatric patients below the age of 16 have not been established.
PREGNANCY
Pregnancy Teratogenic Effects 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.
robaxin ® and robaxin ® -750 should be given to a pregnant woman only if clearly needed.
Safe use of robaxin ® and robaxin ® -750 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, robaxin ® and robaxin ® -750 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 ).
NUSRING MOTHERS
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 robaxin ® or robaxin ® -750 is administered to a nursing woman.
INFORMATION FOR PATIENTS
Information for Patients Patients should be cautioned that methocarbamol may cause drowsiness or dizziness, which may impair their ability to operate motor vehicles or machinery.
Because methocarbamol may possess a general CNS-depressant effect, patients should be cautioned about combined effects with alcohol and other CNS depressants.
DOSAGE AND ADMINISTRATION
robaxin ® (methocarbamol), 500 mg – Adults: Initial dosage: 3 tablets q.i.d.
Maintenance dosage: 2 tablets q.i.d.
robaxin ® -750 (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.