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methocarbamol (Rx)Brand and Other Names:Robaxin

 
 
 

Dosing & Uses

AdultPediatricGeriatric

Dosage Forms & Strengths

tablet

  • 500mg
  • 750mg

injectable solution

  • 100mg/mL
more...

Muscle Spasm

1 g IV/IM; additional doses at q8hr until PO; not to exceed 3 g/day

Total parenteral dose SHOULD NOT EXCEED 3 g/day for >3 days, unless treating tetanus; if condition persists, may repeat therapy after drug-free interval of 48 hr

1500 mg PO q6hr for 48-72 hours; not to exceed 8 g/day THEN decrease to 4-4.5 g/day divided q4-8hr

Tetanus

Adjunct therapy: Initial 1-2 g IV injection (at 300 mg/min), THEN

Additional 1-2 g IV infusion for total dose of 3 g initially

May repeat 1-2 g IV q6hr until can give NG or PO

Total of 24 g PO may be needed

Dosing Modifications

Renal failure: Not studied; parenteral dosage form contraindicated due to presence of polyethylene glycol

Hepatic failure: Not studied

Dosage Forms & Strengths

tablet

  • 500mg
  • 750mg

injectable solution

  • 100mg/mL
more...

Tetanus

15 mg/kg/dose IV q6hr PRN or 500 mg/m²/dose; not to exceed 1.8 g/m²/day for 3 days only 

Muscle Spasm

<16 years: Safety and efficacy not established

>16 years: 1500 mg PO q6hr for 48-72 hours; not to exceed 8 g/day THEN decrease to 4-4.5 g/day divided q4-8hr

Considered safe in elderly because of short half-life

Muscle Spasm

500 mg PO q6hr; may gradually titrate dose to response

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Interactions

Interaction Checker

methocarbamol and

No Results

     
     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

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            Adverse Effects

            Frequency Not Defined

            Drowsiness

            Dizziness

            Leukopenia (IV)

            Lightheadedness

            Blurred vision

            Headache

            Fever

            Nausea

            Anorexia

            Adynamic ileus

            Dysgeusia

            GI upset

            Nystagmus

            Diplopia

            Flushing

            Vertigo

            Mild muscular incoordination

            Syncope

            Hypotension

            Bradycardia

            Urticaria

            Pruritus

            Rash

            Skin eruptions

            Conjunctivitis with nasal congestion

            Anaphylactic reactions

            Thrombophlebitis (IV)

            Sloughing (IV)

            Injection site pain (IV)

            Hemolysis (IV)

            Increased Hgb and RBCs in urine (IV)

            Seizures (IV)

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            Warnings

            Contraindications

            Hypersensitivity

            Renal impairment (parenteral)

            Cautions

            May cause drowsiness/dizziness; patients should not ingest alcohol or other CNS depressants

            May take with food to avoid stomach upset

            Half-life increases with hepatic impairment

            IV formulation not for use in renal impairment (contains polyethylene glycol; injection rate should not exceed 3 mL/min

            May interfere with screening tests for 5-HIAA and vanillylmandelic acid (VMA)

            Use injection with caution in patients with a history of seizures

            Sedative effects potentiated when used with other sedatives

            Medication is poorly tolerated in the elderly

            Pediatric IV dosing approved only for tetanus

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            Pregnancy & Lactation

            Pregnancy category: C

            Lactation: Not known if excreted in breast milk; use caution

            Pregnancy Categories

            A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA:Information not available.

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            Pharmacology

            Mechanism of Action

            Unknown; possibly general CNS depression induces skeletal muscle relaxation

            Absorption

            Onset: 30 min

            Peak serum time: 1-2 hr

            Peak plasma concentration: 16.5-29.8 mcg/mL

            Protein binding: 46-50%

            Metabolism

            Liver (dealkylation and hydroxylation)

            Metabolites: Glucuronide and sulfate conjugates of 3-(2-hydroxyphenoxy)-1,2-propanediol-1-carbamate and 3-(4-hydroxy-2-methoxyphenoxy)-1,2-propanediol-1-carbamate; unidentified metabolites

            Elimination

            Half-life: 0.9-1.8 hr

            Excretion: Urine

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            Administration

            IV Administration

            Direct IV: Administer undiluted at not to exceed 3 mL (=300 mg undiluted)/min

            Infusion: Dilute 1 g with up to 250 mL D5W or NS; avoid extravasation, since injection is hypertonic

            Monitor closely for extravasation

            Administer IV while in recumbent position

            Maintain position 15-30 min following infusion

            IM Administration

            Not to exceed 500 mg (5 mL undiluted) should be given into each gluteal region

            Storage

            Injection when diluted to 4 mg/mL in SWI, D5W, or NS is stable for 6 days at room temperature

            Do not refrigerate after dilution

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            Images

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            Formulary

            FormularyPatient Discounts

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            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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