Methocarbamol

What is methocarbamol?

Methocarbamol is an antispasmodic drug with both sedative and muscle relaxant properties.

It is typically used for muscle pain to relax the musculoskeletal system.¹

It doesn’t directly affect the muscles but works by blocking pain signals sent from the nervous system to the brain.

What is methocarbamol used to treat?

Methocarbamol is approved by the US Food and Drug Administration (FDA) as an adjunct medicine for the treatment of pain from muscle strain and spasms.² It is intended for use alongside rest and physical therapy for the acute treatment of these conditions.

The drug is also used with other medications to relieve painful muscle spasms in tetanus (lockjaw).

Methocarbamol is sometimes prescribed by doctors for off-label (not FDA-approved) uses, such as myofascial pain, rib fractures, arthritis, postoperative hip and knee replacement procedures, and fibromyalgia.³

Dosage forms and strengths

Methocarbamol comes in both pill and injectable forms. The latter can only be administered by a healthcare professional.

In the United States, methocarbamol pills are available in two different strengths:

• 500mg

• 750mg

The injectable form comes in one concentration of 100mg/mL.

Your doctor will determine your strength and dosage depending on the type and severity of the problem being treated and any other health issues you have.

You may need a reduced dosage if you’re over the age of 65 or you have kidney or liver problems.

How do you take methocarbamol?

Contact your pharmacist or doctor if you have any initial questions about your methocarbamol prescription. Otherwise, follow your doctor’s instructions on how many pills you should take and how often. These should be on your pill bottle.

Read the recommended schedule carefully, as your dose may decrease after two or three days.

Methocarbamol can be taken with or without food. You can take the pills whole or cut or crush them if it makes them easier to swallow.

Try to take your medication at about the same time each day. If you’re prescribed more than one daily dose, try to space your doses evenly.

A medical professional will determine your dosage if you’re receiving the intravenous formulation.

Seeing results

Methocarbamol is a fairly fast-acting drug.

The drug starts working about 30 minutes after you take the pill version.⁴

An hour or two after taking your dose, the drug level peaks, and you may start to observe a notable improvement in your symptoms.

Who should not take methocarbamol?

Some people may not benefit from taking methocarbamol because they have medical conditions that interfere with its action. This includes people with any of the following:⁵

• A known allergy to methocarbamol or any ingredients in your prescribed tablet

• Kidney disease

• Myasthenia gravis

The drug should be used with caution by people

• With liver disease

• With an alcohol or substance use disorder

• Taking other sedatives or pain medications

• With a seizure disorder

• Aged 65 and older

• Who operate machinery, drive, or perform hazardous activities

• Who are pregnant or breastfeeding

• Who are planning a pregnancy

In general, oral methocarbamol is not prescribed for anyone under the age of 16 because its safety and effectiveness have not been determined in this age group.⁶

Potential side effects of methocarbamol

Methocarbamol has potential sedating effects. Driving or operating dangerous machinery is not recommended until you know how the medication affects you.

Side effects of methocarbamol typically fall into the following categories:⁷

Common side effects

Most of methocarbamol’s side effects are mild and go away after a few days or weeks. If your symptoms persist, talk to your doctor about what you can do to alleviate them.

Common side effects from oral methocarbamol include the following:

• Drowsiness

• Headache

• Dizziness

• Sedation

• Lightheadedness

• Nausea, vomiting

• Metallic taste

• Discolored urine

• Flushing

• Hives or another type of skin rash

• Low blood pressure

• Blurred vision

Severe side effects

Severe adverse effects from oral methocarbamol include but are not limited to the following:

• Allergic reaction

• Fainting

• Low blood pressure

• Slowed heart rate

• Edema (water retention, swollen tissues)

• Jaundice (yellowing of the skin or eyes)

• Confusion, loss of memory

• Seizures

• Vertigo, lack of coordination

• Sleeplessness

• Low white blood cell count

• Dyskinesia (a movement disorder)

• Blocked bile duct

When to seek medical attention

Talk to your doctor if you have any common mild side effects and they are bothersome or don’t improve with time. Your doctor may decide to switch you to another medication.

If you experience severe adverse effects or an allergic reaction to methocarbamol, seek immediate medical attention or call 911.

Overdose

Symptoms of a methocarbamol overdose include any of the following:⁸

• Nausea

• Sedation

• Blurry vision

• Severe dizziness

• Seizures

• Low blood pressure

• Loss of consciousness

If you believe you might have overdosed on methocarbamol, you should seek immediate medical attention by going to the nearest emergency department, calling the National Poison Control helpline at 1-800-222-1222, or call 911.⁹

Allergy information

Symptoms of an allergic reaction to methocarbamol include one or more of the following:

• Rash, hives

• Itchiness

• Nausea, vomiting

• Swelling of your tongue, throat, or face

• Difficulty breathing, wheezing

• Loss of consciousness

If you develop a severe rash or have any other symptoms of an allergic reaction to methocarbamol, stop taking the drug and immediately seek medical attention.

Call 911 or go to the nearest emergency department if your symptoms are severe or you believe they may be life-threatening.

Pregnancy category

Methocarbamol has been designated as a pregnancy category C medication.¹⁰ This means there are no satisfactory studies in pregnant women. Animal studies have shown the drug crosses the placenta and is found in breast milk.

Methocarbamol and pregnancy

There haven’t been enough human studies carried out to determine if methocarbamol can harm a developing fetus. The risk of taking this medication while pregnant is unknown.

Be sure to tell your doctor if you’re pregnant or thinking about becoming pregnant. Doing so will enable them to determine if the benefits of taking this medication during your pregnancy may outweigh any potential risks.

Methocarbamol and breastfeeding

This drug has been shown to excrete through the milk of dogs. Whether or not it passes into human breast milk is unknown, so it’s best to use methocarbamol with caution.¹¹

If you’re breastfeeding or planning to breastfeed, be sure to tell your doctor before taking this medication. Your doctor may decide to prescribe you an alternative.

Missed doses

You can call your pharmacist or doctor for help if you’re not sure what to do after a missed dose.

In general, if you miss a dose and remember when you’re more than halfway to the time of your next dose, wait and take your next dose as usual.

If you are under halfway to your next dose, take your missed dose straight away, then take your next dose according to your regular schedule.

Don’t take two doses at once to make up for one you missed. Doing so could result in an overdose.

Drug interactions

You should always tell your doctor about anything else you are taking before starting on this medication. Be sure to tell them about any prescription drugs, over-the-counter drugs, herbal remedies, or nutritional supplements you are taking.

Some substances can increase methocarbamol’s adverse effects, while others may not be as effective when mixed with this drug.

The following is a partial list of medications to use with caution or avoid while taking methocarbamol:¹²

• Pyridostigmine bromide (Mestinon, Regonol)

• Metoclopramide (Reglan)

• Antinausea drugs, such as promethazine (Phenergan)

• Amifampridine (Firdapse)

• Drugs for pain, such as tramadol, morphine, hydrocodone, and gabapentin

• Tricyclic antidepressants, such as doxepin (Silenor), amitriptyline (Elavil), and imipramine (Tofranil)

• Monoamine oxidase inhibitors (MAOIs), such as tranylcypromine (Parnate) and phenelzine (Nardil)

• Drugs to alleviate anxiety, such as alprazolam (Xanax), diazepam (Valium), and clonazepam (Klonopin)

• Antipsychotic medications, such as olanzapine (Zyprexa)

• Drugs for insomnia, such as doxylamine (Unisom) and doxepin (Silenor)

• Herbal supplements, such as valerian root and kava-kava

Can I drink alcohol while taking methocarbamol?

It is not considered safe to drink alcohol while taking methocarbamol. Alcohol can intensify some of this medication’s side effects.

What to discuss with your doctor before starting methocarbamol

Before taking methocarbamol, speak to your doctor about the following things:

• Any health conditions you have, particularly a kidney or liver condition, muscle disease, sleep problem, seizure disorder, or any condition you take pain medicines or sedatives for

• Any medication allergies you have

• All medications you’re currently taking, either regularly or occasionally, as well as any herbal or nutritional supplements

• If you’re pregnant or breastfeeding, or if you’re planning on becoming pregnant soon

• If you drink alcohol or use cannabis or other illicit drugs

• If you have a job requiring you to drive, operate heavy machinery, or perform hazardous tasks

Drug approval history

Methocarbamol was approved by the FDA in 1957.¹³

Tips for taking methocarbamol

• Methocarbamol can be taken with or without food.

• Don’t drive or operate dangerous machinery until you know how methocarbamol affects you.

• Don’t drink alcohol while taking this medication.

• If you miss a dose, don’t double your next dose.

• Try to take your doses at about the same time every day.

• You can cut or crush methocarbamol pills if it makes them easier to swallow.

• Store your medication at room temperature, away from direct light and moisture (don’t store it in the bathroom).

• If you find out you are pregnant, stop taking the medication and contact your doctor.

• If you have any questions about taking methocarbamol, check with your pharmacist or doctor. They want you to have success with your medication so that you can feel better.