Methocarbamol 500mg Tablets
It is used to relax muscles.
Drug Class
Skeletal Muscle Relaxant
Pharmacologic Class
Centrally Acting Skeletal Muscle Relaxant
Pregnancy Category
Category C
FDA Approved
Jul 1957
DEA Schedule
Not Controlled
Overview
What is this medicine?
Methocarbamol is a medication used to relax muscles and relieve discomfort caused by muscle spasms, often due to injuries or strains. It works by affecting the brain and nervous system to help relax the muscles.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. If it causes stomach upset, taking it with food may help.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry location, avoiding the bathroom. Keep all medications in a safe place, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so. Instead, consult your pharmacist for guidance on the best disposal method. You may also have access to local drug take-back programs.
Missing a Dose
If you take this medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. If it causes stomach upset, taking it with food may help.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry location, avoiding the bathroom. Keep all medications in a safe place, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so. Instead, consult your pharmacist for guidance on the best disposal method. You may also have access to local drug take-back programs.
Missing a Dose
If you take this medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
Lifestyle & Tips
- Avoid alcohol and other CNS depressants (e.g., sedatives, tranquilizers) while taking this medication, as it can increase drowsiness and dizziness.
- Do not drive or operate heavy machinery until you know how this medication affects you, as it can cause drowsiness, dizziness, and blurred vision.
- Take with food or milk if stomach upset occurs.
- Do not stop taking this medication suddenly without consulting your doctor, especially if you have been taking it for a prolonged period.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
Initial: 1500 mg (3 tablets) four times a day for 2 to 3 days. Maintenance: 1000 mg (2 tablets) four times a day, or 750 mg (1.5 tablets) four times a day, or 1000 mg (2 tablets) three times a day.
Dose Range:
3000 - 4500 mg
Condition-Specific Dosing:
acute_muscle_spasm:
Initial: 1500 mg QID for 2-3 days. Maintenance: 1000 mg QID or 750 mg QID or 1000 mg TID.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established (Safety and efficacy not established in children under 16 years of age)
Adolescent:
Not established (Safety and efficacy not established in children under 16 years of age)
Dose Adjustments
Renal Impairment:
Mild:
No specific dose adjustment recommended, but use with caution.
Moderate:
Use with caution; consider lower doses and monitor for adverse effects due to potential accumulation of metabolites.
Severe:
Contraindicated or not recommended due to potential accumulation of metabolites and increased risk of toxicity.
Dialysis:
Methocarbamol and its metabolites are dialyzable to a limited extent. Use with caution, monitor for adverse effects.
Hepatic Impairment:
Mild:
No specific dose adjustment recommended, but use with caution.
Moderate:
Use with caution; consider lower doses and monitor for adverse effects due to impaired metabolism.
Severe:
Use with caution; consider lower doses and monitor for adverse effects due to impaired metabolism. Avoid if severe impairment.
Pharmacology
Mechanism of Action
Methocarbamol is a centrally acting skeletal muscle relaxant. Its exact mechanism of action is not fully understood but is believed to be due to general central nervous system (CNS) depression rather than a direct effect on the skeletal muscles themselves or on the motor end plate. It produces skeletal muscle relaxation by depressing polysynaptic reflexes in the spinal cord and subcortical areas of the brain.
Pharmacokinetics
Absorption:
Bioavailability:
Not available (Rapidly and almost completely absorbed)
Tmax:
1 to 2 hours
FoodEffect:
Food may slightly increase absorption, but generally not clinically significant.
Distribution:
Vd:
Not available (Widely distributed)
ProteinBinding:
46% to 50%
CnssPenetration:
Yes
Elimination:
HalfLife:
1 to 2 hours
Clearance:
Not available
ExcretionRoute:
Renal (primarily as metabolites)
Unchanged:
<1%
Pharmacodynamics
OnsetOfAction:
Within 30 minutes
PeakEffect:
Within 2 hours
DurationOfAction:
Approximately 4 to 6 hours
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Help Right Away
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor immediately or seek emergency medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Feeling extremely tired or weak
Yellowing of the skin or eyes (jaundice)
Seizures
Severe dizziness or fainting
Slow heartbeat (bradycardia)
Fever, chills, or sore throat
Memory problems or loss
Confusion
Changes in vision
Inability to control eye movements
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms, contact your doctor for advice:
Upset stomach or vomiting
Dizziness or drowsiness
Headache
Flushing
Trouble sleeping (insomnia)
Stuffy nose
Metallic taste
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor immediately or seek emergency medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Feeling extremely tired or weak
Yellowing of the skin or eyes (jaundice)
Seizures
Severe dizziness or fainting
Slow heartbeat (bradycardia)
Fever, chills, or sore throat
Memory problems or loss
Confusion
Changes in vision
Inability to control eye movements
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms, contact your doctor for advice:
Upset stomach or vomiting
Dizziness or drowsiness
Headache
Flushing
Trouble sleeping (insomnia)
Stuffy nose
Metallic taste
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Signs of an allergic reaction (hives, difficulty breathing, swelling of your face, lips, tongue, or throat)
- Severe dizziness or fainting
- Unusual weakness or tiredness
- Yellowing of the skin or eyes (jaundice)
- Dark urine
- Seizures
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This is crucial to ensure safe use and avoid potential interactions.
* Any existing health problems, as this medication may interact with other medical conditions.
To guarantee your safety, carefully review all your medications and health issues with your doctor and pharmacist. Do not initiate, discontinue, or modify the dosage of any medication without first consulting your doctor to confirm it is safe to do so.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This is crucial to ensure safe use and avoid potential interactions.
* Any existing health problems, as this medication may interact with other medical conditions.
To guarantee your safety, carefully review all your medications and health issues with your doctor and pharmacist. Do not initiate, discontinue, or modify the dosage of any medication without first consulting your doctor to confirm it is safe to do so.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Before engaging in activities that require your full attention, such as driving, wait until you understand how this drug affects you.
Be aware that this medication may influence the results of certain laboratory tests. Therefore, it is crucial to notify all your healthcare providers and laboratory personnel that you are taking this drug.
Prior to consuming alcohol, using marijuana or other cannabis products, or taking prescription or over-the-counter medications that may impair your reactions, consult with your doctor. This medication is typically used in conjunction with rest, physical therapy, pain management medications, and other therapeutic interventions.
If you are pregnant or become pregnant while taking this medication, it is vital to contact your doctor immediately, as it may pose a risk to the unborn baby. Additionally, if you are breastfeeding, discuss the potential risks to your baby with your doctor, as you will need to weigh the benefits and risks of continuing treatment.
Be aware that this medication may influence the results of certain laboratory tests. Therefore, it is crucial to notify all your healthcare providers and laboratory personnel that you are taking this drug.
Prior to consuming alcohol, using marijuana or other cannabis products, or taking prescription or over-the-counter medications that may impair your reactions, consult with your doctor. This medication is typically used in conjunction with rest, physical therapy, pain management medications, and other therapeutic interventions.
If you are pregnant or become pregnant while taking this medication, it is vital to contact your doctor immediately, as it may pose a risk to the unborn baby. Additionally, if you are breastfeeding, discuss the potential risks to your baby with your doctor, as you will need to weigh the benefits and risks of continuing treatment.
Overdose Information
Overdose Symptoms:
- Extreme drowsiness
- Loss of muscle control or coordination (ataxia)
- Blurred vision
- Hypotension (low blood pressure)
- Seizures
- Coma
- Respiratory depression
What to Do:
Seek immediate medical attention or call Poison Control at 1-800-222-1222. Treatment is generally supportive, including gastric lavage, activated charcoal, and maintenance of vital signs.
Drug Interactions
Major Interactions
Moderate Interactions
- Anticholinergic agents: May enhance anticholinergic effects.
- Pyridostigmine bromide: Methocarbamol may inhibit the effect of pyridostigmine bromide, particularly in patients with myasthenia gravis.
Monitoring
Baseline Monitoring
Baseline pain and muscle spasm assessment
Rationale: To establish a starting point for evaluating treatment efficacy.
Timing: Prior to initiation of therapy
Routine Monitoring
Efficacy (reduction in pain/spasm)
Frequency: Daily or as clinically indicated
Target: Subjective improvement
Action Threshold: Lack of improvement or worsening symptoms may require re-evaluation of therapy.
Adverse CNS effects (drowsiness, dizziness, lightheadedness)
Frequency: Daily or as clinically indicated
Target: Minimal to no symptoms
Action Threshold: Significant or intolerable symptoms may require dose reduction or discontinuation.
Gastrointestinal upset (nausea, dyspepsia)
Frequency: Daily or as clinically indicated
Target: Minimal to no symptoms
Action Threshold: Persistent or severe symptoms may require symptomatic treatment or discontinuation.
Symptom Monitoring
- Drowsiness
- Dizziness
- Lightheadedness
- Nausea
- Vomiting
- Dyspepsia
- Blurred vision
- Headache
- Allergic reactions (rash, itching, swelling, severe dizziness, trouble breathing)
Special Patient Groups
Pregnancy
Category C. Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Trimester-Specific Risks:
First Trimester:
Potential for fetal harm based on animal data; use only if clearly needed.
Second Trimester:
Potential for fetal harm based on animal data; use only if clearly needed.
Third Trimester:
Potential for fetal harm based on animal data; use only if clearly needed. Risk of neonatal CNS depression if used close to delivery.
Lactation
L3 (Moderately Safe). Methocarbamol and/or its metabolites are excreted in breast milk. Use with caution; monitor infant for sedation or feeding difficulties. Consider alternative if possible, especially in preterm or neonates.
Infant Risk:
Low to moderate risk of sedation, lethargy, or poor feeding in the infant. Monitor closely.
Pediatric Use
Safety and effectiveness in pediatric patients below the age of 16 years have not been established. Not recommended for use in this population.
Geriatric Use
Geriatric patients may be more sensitive to the CNS depressant effects (drowsiness, dizziness, confusion) of methocarbamol. Lower doses may be required, and careful monitoring is recommended to minimize the risk of falls and other adverse events.
Clinical Information
Clinical Pearls
- Methocarbamol is generally considered less sedating than some other muscle relaxants (e.g., carisoprodol, cyclobenzaprine), but sedation is still a common side effect.
- It is typically used for short-term relief of acute, painful musculoskeletal conditions.
- Advise patients to avoid activities requiring mental alertness until they know how the drug affects them.
- Patients should be advised that urine may turn green, brown, or black upon standing, which is a harmless effect of the drug.
Alternative Therapies
- Cyclobenzaprine
- Tizanidine
- Baclofen
- Carisoprodol
- Metaxalone
- Orphenadrine
- Non-pharmacological therapies (e.g., rest, physical therapy, heat/cold application)
Cost & Coverage
Average Cost:
$10 - $30 per 30 tablets (generic 500mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (most insurance plans)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it's a good idea to check with your pharmacist. If you have any questions or concerns about this medication, don't hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide information about the medication taken, the amount, and the time it happened.