Methocarbamol 100mg/ml Inj, 10ml
It is used to relax muscles.
Drug Class
Skeletal Muscle Relaxant
Pharmacologic Class
Centrally Acting Skeletal Muscle Relaxant
Pregnancy Category
C
FDA Approved
Jul 1957
DEA Schedule
Not Controlled
Overview
What is this medicine?
Methocarbamol injection is a medication given by a healthcare professional to help relax muscles and relieve pain and stiffness caused by muscle spasms. It works by affecting your brain and nervous system to calm muscle activity.
How to Use This Medicine
To use this medication correctly, follow your doctor's instructions and carefully read all accompanying information. Take this medication exactly as directed, and adhere to all provided guidelines. This medication is administered via injection into a muscle or vein.
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the proper storage procedure.
If you miss a dose, contact your doctor promptly to receive guidance on the appropriate course of action.
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the proper storage procedure.
If you miss a dose, contact your doctor promptly to receive guidance on the appropriate course of action.
Lifestyle & Tips
- Avoid alcohol and other CNS depressants (e.g., sedatives, tranquilizers, opioids) as they 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 and dizziness.
- Report any unusual or severe side effects to your doctor immediately.
- Stand up slowly from a sitting or lying position to avoid dizziness or lightheadedness.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
Initial 1 g (10 mL) IV or IM, repeated every 8 hours for severe conditions, up to a maximum of 3 g/day for 3 consecutive days. May be repeated after a 48-hour drug-free interval.
Dose Range:
1000 - 3000 mg
Condition-Specific Dosing:
Acute Musculoskeletal Conditions:
Initial 1 g (10 mL) IV or IM, repeated every 8 hours for severe conditions, up to a maximum of 3 g/day for 3 consecutive days. For milder conditions, 1 g (10 mL) IV or IM once daily for 3 days. IV infusion rate should not exceed 3 mL/minute (300 mg/minute).
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established (Not recommended for children under 12 years of age)
Adolescent:
Not established (Not recommended for children under 12 years of age)
Dose Adjustments
Renal Impairment:
Mild:
Use with caution; dose adjustment may be necessary due to potential for accumulation of metabolites.
Moderate:
Use with caution; dose adjustment may be necessary due to potential for accumulation of metabolites.
Severe:
Contraindicated in severe renal impairment due to accumulation of polyethylene glycol 300 (vehicle) which can cause metabolic acidosis.
Dialysis:
Not dialyzable. Contraindicated in severe renal impairment.
Hepatic Impairment:
Mild:
Use with caution; dose adjustment may be necessary due to impaired metabolism.
Moderate:
Use with caution; dose adjustment may be necessary due to impaired metabolism.
Severe:
Use with caution; dose adjustment may be necessary due to impaired metabolism.
Pharmacology
Mechanism of Action
Methocarbamol is a centrally acting skeletal muscle relaxant. Its exact mechanism of action is not fully understood but is thought to be due to general central nervous system (CNS) depression. It does not directly relax tense skeletal muscles or produce direct relaxation of the motor endplate. It reduces skeletal muscle spasm through its depressant action on the CNS, particularly at the brain stem and spinal cord levels.
Pharmacokinetics
Absorption:
Bioavailability:
Not available (IV/IM administration)
Tmax:
Rapid (IV), ~30 minutes (IM)
FoodEffect:
Not applicable for injection
Distribution:
Vd:
Not available
ProteinBinding:
46% to 50%
CnssPenetration:
Yes
Elimination:
HalfLife:
Approximately 1 to 2 hours
Clearance:
Not available
ExcretionRoute:
Renal (primarily as metabolites, small amount as unchanged drug)
Unchanged:
<1% (oral), specific for injection not readily available but expected to be low
Pharmacodynamics
OnsetOfAction:
Rapid (IV), within 30 minutes (IM)
PeakEffect:
Not precisely defined, correlates with onset
DurationOfAction:
Approximately 4 to 6 hours
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Help Immediately
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention right away:
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
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 mild 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 that bother you or do not go away, contact your doctor:
Upset stomach or vomiting
Dizziness or drowsiness
Headache
Flushing
Trouble sleeping
Stuffy nose
Metallic taste
* Irritation at the injection site
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 or seek medical attention right away:
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
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 mild 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 that bother you or do not go away, contact your doctor:
Upset stomach or vomiting
Dizziness or drowsiness
Headache
Flushing
Trouble sleeping
Stuffy nose
Metallic taste
* Irritation at the injection site
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:
- Severe dizziness or fainting
- Extreme drowsiness or sedation
- Blurred vision or double vision
- Rash, itching, or hives (signs of allergic reaction)
- Difficulty breathing or swallowing
- Slow heartbeat
- Seizures
- Yellowing of skin or eyes (jaundice)
- Unusual bleeding or bruising
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 symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist identify potential interactions between this medication and other substances.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that it is safe to take this medication with all your current medications and health conditions. Never start, stop, or change the dose of any medication without first consulting 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 symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist identify potential interactions between this medication and other substances.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that it is safe to take this medication with all your current medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all of your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. If you have a known latex allergy, consult with your doctor, as some products may contain latex.
To ensure your safety, avoid operating a vehicle or engaging in activities that require alertness until you understand how this medication affects you. Additionally, be aware that this drug may interfere with certain laboratory tests, so it is crucial to notify all healthcare providers and laboratory personnel that you are taking this medication.
Before consuming alcohol, using marijuana or other cannabis products, or taking prescription or over-the-counter medications that may cause drowsiness, 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. 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.
To ensure your safety, avoid operating a vehicle or engaging in activities that require alertness until you understand how this medication affects you. Additionally, be aware that this drug may interfere with certain laboratory tests, so it is crucial to notify all healthcare providers and laboratory personnel that you are taking this medication.
Before consuming alcohol, using marijuana or other cannabis products, or taking prescription or over-the-counter medications that may cause drowsiness, 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. 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 tone
- Profound weakness
- Nausea
- Vomiting
- Blurred vision
- Hypotension
- Bradycardia
- Seizures
- Coma
- Respiratory depression
What to Do:
Seek immediate medical attention. Call 911 or your local emergency number. For poison control, call 1-800-222-1222. Treatment is symptomatic and supportive, including maintaining an open airway, monitoring vital signs, and IV fluids. Hemodialysis is not effective.
Drug Interactions
Major Interactions
- CNS depressants (e.g., alcohol, barbiturates, opioids, benzodiazepines, tricyclic antidepressants, antihistamines): Increased CNS depression, including respiratory depression and sedation.
- Pyridostigmine bromide: May antagonize the effects of pyridostigmine bromide, particularly in patients with myasthenia gravis.
Moderate Interactions
- Anticholinergic agents: May enhance anticholinergic effects.
- Skeletal muscle relaxants (other): Additive CNS depression.
Monitoring
Baseline Monitoring
Renal function (BUN, creatinine)
Rationale: To assess kidney function, especially important due to polyethylene glycol 300 vehicle in injection which can accumulate in renal impairment.
Timing: Prior to initiation, especially if prolonged use or risk factors for renal impairment.
Hepatic function (ALT, AST, bilirubin)
Rationale: To assess liver function, as methocarbamol is metabolized in the liver.
Timing: Prior to initiation, especially if prolonged use or risk factors for hepatic impairment.
Vital Signs (Blood Pressure, Heart Rate, Respiratory Rate)
Rationale: To establish baseline and monitor for potential adverse effects like hypotension or respiratory depression.
Timing: Prior to administration.
Routine Monitoring
Level of consciousness/Sedation
Frequency: During and after administration, then periodically as clinically indicated.
Target: Alert and oriented, or appropriate level of sedation for condition.
Action Threshold: Excessive sedation, somnolence, or unresponsiveness; consider dose reduction or discontinuation.
Muscle spasm relief
Frequency: Periodically throughout therapy.
Target: Reduction in muscle spasm and associated pain.
Action Threshold: Lack of therapeutic effect after appropriate trial; consider alternative therapy.
Vital Signs (Blood Pressure, Heart Rate, Respiratory Rate)
Frequency: During and after administration, then periodically as clinically indicated.
Target: Within patient's normal range.
Action Threshold: Significant hypotension, bradycardia, or respiratory depression; intervene as appropriate.
Injection site for extravasation or thrombophlebitis
Frequency: During and after IV administration.
Target: No signs of redness, swelling, pain, or induration.
Action Threshold: Signs of extravasation or thrombophlebitis; discontinue infusion and manage locally.
Symptom Monitoring
- Dizziness
- Drowsiness
- Nausea
- Vomiting
- Headache
- Blurred vision
- Fever
- Allergic reactions (rash, itching, swelling, severe dizziness, trouble breathing)
- Bradycardia
- Hypotension
- Seizures
Special Patient Groups
Pregnancy
Category C. Should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans.
Trimester-Specific Risks:
First Trimester:
Potential for fetal harm, use only if clearly indicated.
Second Trimester:
Potential for fetal harm, use only if clearly indicated.
Third Trimester:
Potential for fetal harm, use only if clearly indicated. Risk of neonatal CNS depression if used close to delivery.
Lactation
Methocarbamol and/or its metabolites are excreted in human milk. Due to the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Infant Risk:
L3 (Moderate risk) - Potential for infant sedation, poor feeding, or other CNS effects. Monitor infant for drowsiness, lethargy, or poor feeding.
Pediatric Use
Safety and effectiveness in pediatric patients under 12 years of age have not been established. Not recommended for use in this population.
Geriatric Use
Elderly patients may be more susceptible to the CNS depressant effects (e.g., dizziness, drowsiness, confusion) and orthostatic hypotension. Lower doses may be required. Use with caution.
Clinical Information
Clinical Pearls
- Methocarbamol injection is for short-term use (typically up to 3 days) for acute, severe musculoskeletal conditions.
- Administer IV slowly (no faster than 3 mL/minute or 300 mg/minute) to avoid adverse reactions such as syncope, bradycardia, and hypotension.
- Avoid extravasation during IV administration; monitor injection site closely.
- Urine may turn brown, black, or green upon standing due to a metabolite; this is a harmless effect.
- Due to the polyethylene glycol 300 vehicle, methocarbamol injection is contraindicated in patients with severe renal impairment due to the risk of metabolic acidosis.
Alternative Therapies
- Cyclobenzaprine (Flexeril)
- Tizanidine (Zanaflex)
- Baclofen (Lioresal)
- Carisoprodol (Soma)
- Metaxalone (Skelaxin)
- Orphenadrine (Norflex)
- Non-pharmacological therapies (e.g., physical therapy, heat/cold therapy, rest)
Cost & Coverage
Average Cost:
Varies widely per 10ml vial
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe use, never share your medication with others or take someone else's medication. Store all medications in a secure location, out of reach of children and pets, to prevent accidental ingestion. Dispose of unused or expired medications properly; do not flush them down the toilet or pour them down the drain unless instructed to do so by a healthcare professional or pharmacist. If you are unsure about the correct disposal method, consult your pharmacist, who can also inform you about potential drug take-back programs in your area. Additionally, some medications may come with a separate patient information leaflet, which your pharmacist can provide. If you have any questions or concerns about your medication, discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately contact your local poison control center or seek medical attention. Be prepared to provide information about the medication taken, the quantity, and the time of ingestion.