Robaxin (Methocarbamol) - Oral

What Is Methocarbamol?

Methocarbamol is an oral prescription medication used to treat certain kinds of muscle pain and stiffness. It belongs to a group of drugs commonly referred to as “skeletal muscle relaxants."

Methocarbamol affects the central nervous system (your brain and spinal cord) to relax your skeletal muscles (the muscles you can use voluntarily). It doesn’t affect the muscles that work involuntarily, such as the ones that move food through your gastrointestinal tract. Scientists don’t completely understand exactly how methocarbamol works.

Methocarbamol is also called an antispasmodic. Antispasmodic drugs interrupt pain signaling between the muscle and the brain, which helps reduce muscle spasms and pain. This differs from antispasticity skeletal relaxants, which are prescribed for other health conditions.

Oral methocarbamol is available only as a generic drug. It comes in tablet form to be taken by mouth. However, it is also occasionally delivered through an intravenous line or as an injection into a muscle. This article will focus on the oral version of this methocarbamol.

Drug Facts

Generic Name: Methocarbamol

Brand Name(s): Robaxin (discontinued)

Drug Availability: Prescription

Administration Route: Oral

Therapeutic Classification: Skeletal muscle relaxant

Available Generically: Yes

Controlled Substance: N/A

Active Ingredient: Methocarbamol

Dosage Form(s): Tablet

What Is Methocarbamol Used For?

The Food and Drug Administration (FDA) approved methocarbamol to treat sudden muscle or skeletal pain in the related joints, like from an injury such as a muscle strain (also known as a "pulled muscle").

The FDA recommends using methocarbamol in addition to rest, physical therapy, and other interventions to relax muscles.

Methocarbamol's broad indication means the drug can be used in many medical situations. For example, healthcare providers sometimes prescribe muscle relaxants, such as methocarbamol, for people with lower back pain that comes on suddenly, especially if they haven’t responded well to treatments like over-the-counter (OTC) pain relievers. Or, it might be helpful if you injured yourself and have muscle strain or sprain symptoms.

Please note that methocarbamol is NOT usually used for diseases that cause muscle spasticities (a kind of extreme muscle tightness), such as cerebral palsy or multiple sclerosis.

Methocarbamol Drug Information: A person sits with their knee bent and hands on their leg

Verywell / Dennis Madamba

How to Take Methocarbamol

Take methocarbamol exactly as your healthcare provider instructs. It generally doesn’t matter if you take it with or without food.

You will usually take methocarbamol tablets four times a day to start, followed by either three or six times a day. Your healthcare provider will tell you how much to take.

Storage

Store the medication at room temperature, away from excess heat and moisture.

Off-Label Uses

Healthcare providers can prescribe methocarbamol for additional pain problems that have not been technically FDA approved.

For example, methocarbamol might be used for:

The evidence is less clear that methocarbamol is safe and effective for these types of issues.

What Are the Side Effects of Methocarbamol?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

Methocarbamol commonly causes drowsiness or decreased alertness, especially when you first start to take it. Dizziness and lightheadedness are also relatively common issues. It’s important to keep this in mind when you first start taking the drug. For example, it might not be safe for you to drive until you see how the medication affects you. 

Methocarbamol might also turn your urine a different color, like brown, black, or green. This is not a sign of a health problem. Don't be alarmed if this happens.

Severe Side Effects

Most people don’t experience side effects from methocarbamol. However, the drug carries a rare risk of serious symptoms, such as:

  • Severe allergic reaction, which can cause difficulty breathing
  • Low blood pressure, which might cause fainting
  • Seizures
  • Jaundice (yellowing of the skin) from liver disease
  • Disorientation and confusion

Call your healthcare provider promptly if you have potentially serious side effects or side effects that don't get better. Call 911 for potentially life-threatening symptoms, such as difficulty breathing or decreased consciousness.

Long-Term Side Effects

Methocarbamol is only recommended to take for a short time, usually two to three weeks. This is because a person can become physiologically adapted to the drug, leading to substance use disorders. This might be especially likely if methocarbamol is taken for extended periods, not as prescribed (e.g., in higher doses or crushed as pills), or taken with drugs like alcohol.

However, once the drug is completely out of your system, it’s unlikely to cause any long-term issues.

Report Side Effects

Methocarbamol may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Methocarbamol Should I Take?

Drug Content Provided and Reviewed by IBM Micromedex®

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (tablets):
    • For relaxing stiff muscles:
      • Adults—At first, three tablets of 500 milligrams (mg) or two tablets of 750 mg (total dose of 1500 mg) four times a day. Your doctor may adjust your dose as needed.
      • Children—Use and dose must be determined by your doctor.

Modifications

Your dosage of methocarbamol may need to be modified (changed) if you:

  • Are 65 years or older
  • Have liver or kidney problems

Missed Dose

If you miss a dose, take it as soon as you remember. If you are very close to your next dose, just take that dose—do not double up.

Overdose: What Happens If I Take Too Much Methocarbamol?

Overdose symptoms from methocarbamol might include:

  • Sleepiness
  • Nausea
  • Blurred vision
  • Seizures

An extreme overdose might cause coma or even death.

Overdose risks are greater if combining methocarbamol with other drugs known as "CNS depressants," such as alcohol. Taken together in high amounts, such drugs can slow your breathing rate and lead to death.

What Happens If I Overdose on Methocarbamol


If you think you or someone else may have overdosed on methocarbamol, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking methocarbamol, call 911 immediately.

Precautions

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It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

Check with your doctor before using this medicine with alcohol or other medicines that affect the central nervous system (CNS). The use of alcohol or other medicines that affect the CNS with risperidone may worsen the side effects of this medicine, such as dizziness, poor concentration, drowsiness, unusual dreams, and trouble with sleeping. Some examples of medicines that affect the CNS are antihistamines or medicine for allergies or colds, sedatives, tranquilizers, or sleeping medicines, medicine for depression, medicine for anxiety, prescription pain medicine or narcotics, medicine for attention deficit and hyperactivity disorder, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics.

This medicine may cause some people to become dizzy or drowsy. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert.

Make sure any doctor or dentist who treats you knows that you are using this medicine. This medicine may affect the results of certain medical tests. .

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines) and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Take Methocarbamol?

Do not use methocarbamol if you are pregnant, as the drug has a risk of causing abnormalities in the developing fetus unless your healthcare provider determines that the potential benefits outweigh the risks.

It’s also not recommended to take if you are breastfeeding or have a known allergy to the drug or any of its ingredients.

Additionally, methocarbamol should be used with caution in:

  • People with liver or kidney problems
  • People taking drugs for seizures, also known as anticonvulsants or antiepileptic drugs: Due to interactions with these medications, methocarbamol might not work as well if combined with them.
  • People taking medications to treat a medical condition called myasthenia gravis due to potential interactions
  • People with substance use disorder: Although it is not a controlled substance, methocarbamol may have some abuse potential. However, it doesn't appear to be as addictive as benzodiazepines, like Valium (diazepam), or opioids, like Oxycontin (oxycodone).
  • People 65 and older: Methocarbamol can cause dizziness, which may make older individuals more prone to falling.

What Other Medications Interact With Methocarbamol?

People taking methocarbamol need to avoid certain drugs while taking this medication. This is especially important for CNS depressants or drugs that slow brain activity.

CNS depressants include:

  • Alcohol
  • Benzodiazepines like Valium (diazepam)
  • Barbiturate drugs like phenobarbital
  • Other sedative drugs like Ambien (zolpidem)
  • Narcotic cough suppressants like codeine

Taking CNS depressants with methocarbamol can increase the likelihood of overdose or substance abuse problems.

In some cases, like for alcohol, it’s best to avoid the drug completely while using methocarbamol. In other cases, you might be able to use the drug if you work closely with your healthcare provider and take the drugs exactly as prescribed.

Other drugs may interact with methocarbamol and make it less effective or vice versa. Ask your healthcare provider for a full list of drug interactions. Be open and honest with your healthcare team about all prescription and OTC medications and supplements you take.

What Medications Are Similar?

Some muscle relaxants that are similar to methocarbamol include the following:

To be clear, these are possible alternatives to methocarbamol. However, they shouldn’t be taken at the same time.

These medications share similarities to methocarbamol in terms of potential side effects and risks. If you can’t take methocarbamol because of a health condition, none of these other drugs are likely to be good possibilities. Depending on the situation, you might be better off with an entirely different type of drug, like a non-steroidal anti-inflammatory drug, like Advil (ibuprofen).

Compared with the other alternatives, one advantage of methocarbamol is that it tends not to make people as drowsy. Although some drowsiness can still occur, the symptoms tend to be less severe. It may also pose less of a risk in terms of potential abuse or dependence.

Frequently Asked Questions

  • Can I get addicted to methocarbamol?

    Methocarbamol is not as addictive as drugs like benzodiazepines and opioids. However, methocarbamol carries some risk of dependence because of its sedative effects. This is mainly a problem when a person is taking methocarbamol in combination with other drugs, like alcohol. It’s partly because of this issue that healthcare providers often won't prescribe methocarbamol to be taken for an extended time.

  • How long does it take for methocarbamol to work?

    Because of the way methocarbamol is broken down and used in the body, it generally starts to work pretty quickly. It usually starts to work 30 minutes after taking it orally. You might notice improvements within an hour or two, or even less.

  • Is methocarbamol a good option for chronic pain?

    Methocarbamol is not usually a good option for treating chronic pain. However, some healthcare providers will prescribe methocarbamol or other muscle relaxants to people with chronic low back pain. Although this might work for you, be aware that this is an off-label use for methocarbamol and has not been well studied. Also, extended use of this medication carries a greater risk of potential abuse or dependence issues.

    You might also be better off with other interventions, like physical therapy. Work with your healthcare team to figure out the best solution for you.

  • How should I stop taking methocarbamol?

    Stopping this drug abruptly may also cause certain symptoms, especially if you’ve been taking it for an extended time or at very large doses. In extreme cases, this might cause issues such as:

    • Seizures
    • Agitation
    • Insomnia
    • Increased temperature
    • Hallucinations

    Instead of stopping your medication suddenly, work with your healthcare provider to wean yourself off. This will drastically reduce the risk of such symptoms. The good news is that such withdrawal symptoms usually go away within a few days.

  • Can I drink while on methocarbamol?

    Drinking alcohol while on the drug is a bad idea. Using alcohol and methocarbamol can heighten the effects of both drugs and greatly increase your chance of overdose.

How Can I Stay Healthy While Taking Methocarbamol?

When combined with interventions like physical therapy, methocarbamol can be a helpful aid for relieving muscle pain. However, it does have some risks and some potential for abuse, so it’s good to be aware.

Once you start taking methocarbamol, pay attention to how it affects you. Be cautious and don't drive or operate heavy machinery until you know how your body will respond to the medication

For safe use, take methocarbamol only as directed by your healthcare provider. It’s also important to avoid using it with alcohol or other drugs like benzodiazepines or opioids. You’ll also greatly reduce the chance of developing long-term issues by only using the drug for a limited time, usually a maximum of two to three weeks.

If methocarbamol isn't helping you, talk to your healthcare provider about alternative options for pain relief.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Ruth Jessen Hickman, MD
Ruth Jessen Hickman, MD, is a freelance medical and health writer and published book author.