United States - English - NLM (National Library of Medicine)
METHOCARBAMOL- methocarbamol tablet, coated
Methocarbamol tablet, 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 1,2-Propanediol,3-(2-methoxyphenoxy)-,1-Carbamate,(±)-.(or)
(±)-3-(o-Methoxyphenoxy)-1,2-Propanediol 1-carbamate and has the empirical formula C11H15NO5. Its
molecular weight is 241.24g/mol. The structural formula is shown below.
Methocarbamol is a white powder, sparingly soluble in water and in chloroform, soluble in alcohol
(only with heating), insoluble in benzene and in n-hexane.
Methocarbamol tablets, USP are available as 500 mg and 750 mg tablets for oral administration.
Methocarbamol tablets, USP 500 mg are light orange colored, round shaped film coated tablets
debossed with "G" above the score line on one side and "500" on other side.
Methocarbamol tablets, USP 750 mg are light orange colored, caplet shaped film coated tablets
debossed with "G" on one side and "750" on other side.
Methocarbamol tablets, USP 500 mg and 750 mg contain the following inactive ingredients: colloidal
silicon dioxide, maize starch, povidone, sodium lauryl sulfate, sodium starch glycolate, and stearic acid.
The tabets are coated with Aquarius Prime which contains FD&C yellow 6, hydroxypropylcellulose,
hypromellose, polysorbate 80, propylene glycol, and titanium dioxide
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.
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.
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).
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.
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.
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.
Methocarbamol tablets are contraindicated in patients hypersensitive to methocarbamol or to any of the
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 tablets 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).
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.
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.
See WARNINGS and PRECAUTIONSfor 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.
DRUG & OR LABORATORY TEST INTERACTIONS
Methocarbamol may cause color interference in certain screening tests for 5-hydroxyindoleacetic acid
(5-HIAA) using nitrosonaphthol reagent and in screening tests for urinary vanillylmandelic acid (VMA)
using the Gitlow method.
CARCINOGENESIS & MUTAGENESIS & IMPAIRMENT OF FERTILITY
Long-term studies to evaluate the carcinogenic potential of methocarbamol have not been performed.
No studies have been conducted to assess the effect of methocarbamol on mutagenesis or its potential
to impair fertility.
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 should be given to a pregnant woman only if clearly needed.
Safe use of methocarbamol tablet 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 WARNINGS).
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 are administered to a nursing
Safety and effectiveness of methocarbamol tablets in pediatric patients below the age of 16 have not
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,
To report SUSPECTED ADVERSE REACTIONS, contact Granules USA, Inc. at 1-877-770-3183 or
FDA at 1-800-FDA-1088 or www.fda.gov/medwatch
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.
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.
Methocarbamol Tablets, USP 500 mg – Adults:
Initial dosage: 3 tablets 4 times daily
Maintenance dosage: 2 tablets 4 times daily
Methocarbamol Tablets, USP 750 mg – Adults:
Initial dosage: 2 tablets 4 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.
Methocarbamol tablets, USP 500 mg are light orange colored, roundshaped film coated tablets
debossed with "G" above the score line onone side and "500" on other side.
They are supplied as follows
Bottles of 24 tablets
Bottles of 100 tablets N
Bottles of 500 tablets
Bottles of 1000 tablets
Methocarbamol tablets, USP 750 mg are light orange colored, capletshaped film coated tablets
debossed with "G" on one side and"750" on other side.
Bottles of 24 tablets
Bottles of 100 tablets
Bottles of 500 tablets
Bottles of 1000 tablets
Store between 20ºC and 25ºC (68ºF and 77º F)
[see USP Controlled Room Temperature].
Dispense in tight container.
Granules USA, Inc.
Parsippany, NJ 07054
Granules India Limited
Made in India
Issued: January 2017
methocarbamol tablet, coated
Product T ype
HUMAN PRESCRIPTION DRUG
Ite m Code (Source )
NDC:6 19 19 -6 16 (NDC:70 0 10 -770 )
Route of Administration
Active Ingredient/Active Moiety
Basis of Strength
Stre ng th
METHO CARBAMO L (UNII: 125OD7737X) (METHOCARBAMOL - UNII:125OD7737X)
Stre ng th
SILICO N DIO XIDE (UNII: ETJ7Z6 XBU4)
SO DIUM LAURYL SULFATE (UNII: 36 8 GB5141J)
STEARIC ACID (UNII: 4ELV7Z6 5AP)
SO DIUM STARCH GLYCO LATE TYPE A PO TATO (UNII: 58 56 J3G2A2)
STARCH, CO RN (UNII: O8 232NY3SJ)
FD&C YELLO W NO . 6 (UNII: H77VEI9 3A8 )
HYDRO XYPRO PYL CELLULO SE ( 16 0 0 0 0 0 WAMW) (UNII: RFW2ET6 71P)
HYPRO MELLO SE 2 9 10 ( 6 MPA.S) (UNII: 0 WZ8 WG20 P6 )
PRO PYLENE GLYCO L (UNII: 6 DC9 Q16 7V3)
TITANIUM DIO XIDE (UNII: 15FIX9 V2JP)
PO VIDO NE (UNII: FZ9 8 9 GH9 4E)
PO LYSO RBATE 8 0 (UNII: 6 OZP39 ZG8 H)
o ra nge
no sco re
S hap e
S iz e
Marketing Start Date
Marketing End Date
NDC:6 19 19 -6 16 -9 0
9 0 in 1 BOTTLE; Type 0 : No t a Co mbinatio n Pro duct
0 8 /27/20 19
Marke ting Cate gory
Application Numbe r or Monograph Citation
Marke ting Start Date
Marke ting End Date
ANDA20 9 312
0 8 /27/20 19
Ad d re s s
Busine ss Ope rations
Dire c t_Rx
0 79 254320
re pa c k(6 19 19 -6 16 )