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Robaxin-750 Side Effects

Generic name: methocarbamol

Medically reviewed by Drugs.com. Last updated on May 18, 2022.

Note: This document contains side effect information about methocarbamol. Some of the dosage forms listed on this page may not apply to the brand name Robaxin-750.

For the Consumer

Applies to methocarbamol: injection solution

Side effects requiring immediate medical attention

Along with its needed effects, methocarbamol (the active ingredient contained in Robaxin-750) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking methocarbamol:

Incidence not known

  • Black, tarry stools
  • blurred vision
  • changes in skin color
  • chest pain or discomfort
  • chills
  • clay-colored stools
  • confusion
  • convulsions
  • cough
  • dark urine
  • difficulty swallowing
  • dizziness, faintness, or lightheadedness when suddenly getting up from a lying or sitting position
  • drowsiness
  • fast heartbeat
  • fever
  • headache
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • lightheadedness, dizziness, or fainting
  • loss of appetite
  • loss of bladder control
  • loss or problems with memory
  • muscle spasm or jerking of all extremities
  • nausea
  • pain, tenderness, or swelling of the foot or leg
  • painful or difficult urination
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • rash, hives, itching, red skin
  • slow or irregular heartbeat
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • stomach pain
  • sudden loss of consciousness
  • sweating
  • swollen glands
  • tightness in the chest
  • unpleasant breath odor
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting of blood
  • yellow eyes or skin

Get emergency help immediately if any of the following symptoms of overdose occur while taking methocarbamol:

Symptoms of overdose

  • Loss of consciousness
  • shaking or jerking of one area or side of the body

Side effects not requiring immediate medical attention

Some side effects of methocarbamol may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

  • Belching
  • bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
  • burning, dry, or itching eyes
  • discharge, excessive tearing
  • double vision
  • feeling of constant movement of self or surroundings
  • feeling of warmth
  • heartburn
  • indigestion
  • metallic taste
  • redness of the face, neck, arms, and occasionally, upper chest
  • redness, pain, or swelling of the eye, eyelid, or inner lining of the eyelid
  • sensation of spinning
  • stuffy nose
  • trouble sleeping
  • uncontrolled eye movements
  • vomiting

For Healthcare Professionals

Applies to methocarbamol: injectable solution, oral tablet

General

The most commonly reported adverse reaction is headache.[Ref]

Cardiovascular

Some cardiovascular events may have been due to an overly rapid IV injection.

Most syncope cases resulted in spontaneous recovery; however, epinephrine, injectable steroids, and/or injectable antihistamines have been used in some cases.[Ref]

Frequency not reported: Syncope, hypotension, bradycardia, thrombophlebitis[Ref]

Hypersensitivity

Frequency not reported: Anaphylaxis

Nervous system

Convulsions have been reported with IV administration in patients with seizure disorders.[Ref]

Frequency not reported: Dizziness, lightheadedness, headache, drowsiness, mild muscular incoordination, metallic taste, nystagmus, sedation, seizures (including grand mal), tremor[Ref]

Psychiatric

Frequency not reported: Amnesia, confusion, insomnia, restlessness, anxiety

Local

Frequency not reported: Pain and sloughing at the injection site

Dermatologic

Frequency not reported: Urticaria, pruritus, rash, angioneurotic edema[Ref]

Gastrointestinal

Frequency not reported: Dyspepsia, nausea, vomiting, anorexia[Ref]

Other

Frequency not reported: Vertigo, fever[Ref]

Ocular

Frequency not reported: Blurred vision, conjunctivitis, diplopia[Ref]

Hematologic

Frequency not reported: Leukopenia[Ref]

Hepatic

Frequency not reported: Jaundice (including cholestatic jaundice)

Respiratory

Frequency not reported: Nasal congestion, bronchospasm[Ref]

Frequently asked questions

More about Robaxin-750 (methocarbamol)

Patient resources

Professional resources

Other formulations

Related treatment guides

References

1. "Product Information. Robaxin Injectable (methocarbamol)." Whitehall-Robbins, Madison, NJ.

2. "Multum Information Services, Inc. Expert Review Panel"

3. CAMPBELL DJ, SHERBANIUK R, RIGBY J "FALSE POSITIVE REACTION DUE TO METHOCARBAMOL IN THE SCREENING TEST FOR VANILMANDELIC ACID (VMA)." CLIN CHEM 10 (1964): 447-50

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.