Methocarbamol: Uses, Dosage, Side Effects, and Safety Guide

Methocarbamol is a prescription muscle relaxant that is usually used to treat pain and discomfort associated with musculoskeletal disorders (strains, sprains or injuries). It does this by aiding in relaxation of the muscles, which makes it easier to move and recover.

Methocarbamol is commonly marketed as Robaxin and comes in oral tablet and injectable doses, which provides the flexibility of treatment based on patients needs and the severity of the condition. Its application is generally accompanied by rest, physical therapy, and other supportive means to achieve a successful relief.

Table of Contents

How Methocarbamol Works

Methocarbamol is a centrally acting muscle relaxant whose mechanism of action is not clearly understood. It is thought to have its action by general central nervous system (CNS) depression which can include a blockage of nerve impulses in the brain and spinal cord. This will probably decrease muscle spasms and pain. Notably, methocarbamol has no direct action on the contractile responses of striated muscle, the motor end plate, or nerve fibres.

Approved Uses

Methocarbamol is used to treat two things:

Musculoskeletal Conditions

Methocarbamol is prescribed to relieve pain in the case of acute painful musculoskeletal disorders, including muscle strains, sprains or injuries. It is normally used together with rest, physical therapy, and other supportive interventions. Initial oral dosing usually begins at 1500 mg four times a day, and may be increased or decreased depending on the response of the patient. In extreme cases, intravenous or intramuscular use can be taken on short term basis.

Adjunct in Tetanus Treatment

Methocarbamol is also used as a supplement to treat tetanus, which is painful tightening of the muscles. Although it does not substitute conventional therapy including tetanus antitoxin and antibiotics, methocarbamol can aid in the management of neuromuscular symptoms in severe cases. Dosage and administration are closely supervised in a hospital.

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Dosage and Administration

Methocarbamol comes in oral and injectable form, and dosage depends on the condition of the patient. When administered orally, the usual initial dose is 1500 mg four times a day, and the dose can be changed according to the response of the symptoms and tolerance. Maintenance doses tend to be smaller and separated over the day to treat persistent muscle pain or spasms. The injectable type is mainly employed in hospitals with more serious cases.

In this case, methocarbamol may be given as intravenous or intramuscular doses of 1 gramme at a time, not more than 3 grammes in a 24-hour time frame. Treatment is usually short-lasted and often injectable therapy is followed by oral therapy after stabilisation of the patient. Dosing must be prescribed by a health care professional to be safe and effective.

Potential Side Effects

Common Side Effects

Patients may have some mild side effects such as drowsiness, dizziness, blurred vision, headache, or upset stomach. Others might experience nausea, flushing or metallic taste.

Serious Side Effects

More severe reactions are rare, but may happen. These are confusion, hallucinations, jaundice or allergic reactions such as rash, swelling or difficulty breathing. In others, there have been reports of altered heart rate (slow or fast) or hypotension. Emergency medical care should be sought in case of severe reactions.

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Safety Precautions and Warnings

Contraindications

Methocarbamol is contraindicated in people with known allergy (hypersensitivity) to methocarbamol or any of its constituents. In injectable form, one should avoid patients with impaired renal function because of the risk of its excipient. In addition, caution or avoidance is advised in patients with myasthenia gravis, which can cause aggravation of muscle weakness.

Pregnancy and Breastfeeding

Methocarbamol is a Pregnancy Category C medication. Animal research and case reports indicate that there is a potential foetal risk; it is only recommended in pregnancy when the benefits outweigh the risks. It can be transferred to breast milk and may have an effect on a nursing infant, therefore care is required and medical care is necessary.

Alcohol Interaction

Alcohol may increase the sedative effects such as dizziness, drowsiness and loss of coordination when used together with methocarbamol. Do not drink or use alcohol with methocarbamol.

Drug Interactions

Methocarbamol may also interact with a wide variety of other drugs, particularly those that are central nervous system (CNS) depressants.

CNS depressants (e.g., benzodiazepines, opioids, antihistamines, sleep or anxiety medications) can be used concomitantly with methocarbamol to increase sedation, dizziness, or respiratory depression.
Some antidepressants or tricyclics can also be combined to cause CNS depression.
Methocarbamol can also interact with anticholinesterase medications that are taken to treat myasthenia gravis and lower their potency.

Due to this reason, it is important to inform your healthcare provider about all existing prescriptions, over-the-counter medications and supplements before taking methocarbamol.

Alternatives to Methocarbamol

In case of inappropriateness of methocarbamol (side effects, interaction, or response), other muscle relaxants can be used. Cyclobenzaprine (brand names Amrix, Fexmid) is commonly used to treat muscle spasms and acute musculoskeletal pain, and is well-researched.

Sedation is less likely to occur with metaxalone (Skelaxin), which may be the preferred choice during the day. Alternative is Tizanidine, particularly in spasticity related to neurological disorders.

Benzodiazepines such as diazepam are occasionally used, but are more likely to cause dependence and sedation, so are generally only used in the short term or in isolated instances.

You should always discuss with a doctor to select the most appropriate alternative depending on your medical background and condition.

Final Word

Methocarbamol is a good muscle relaxant; it is used to treat pain and spasms caused by musculoskeletal diseases and as an adjunct in treatment of tetanus. It acts by relaxing nerves and there are flexible dosing schedules in oral and injectable forms. Although it is usually safe, it may lead to drowsiness or dizziness and may interact with other drugs or alcohol. Never start or stop taking methocarbamol without consulting a healthcare professional to make sure it fits in your health plan and treatment.

Methocarbamol: Uses, Dosage, Side Effects, and Safety Guide