methocarbamol

Action and Spectrum

Action

The typical duration of methocarbamol prescriptions is a few weeks or less. The dosage and length of treatment will vary depending on the ailment being treated and the specific patient. It is available as an oral tablet or an injectable.

Spectrum

methocarbamol range of activity is essentially constrained to what it does to the skeletal muscular system. Apart than muscle discomfort and spasm, other conditions are not commonly treated with it. Methocarbamol may cause negative effects, just like any drug, therefore patients should speak with their doctor before using it.

Drug Interaction

Adverse Reaction

Frequency not defined 

Drowsiness

Dizziness

Leukopenia (IV)

Fever

Nausea

Anorexia

Lightheadedness

Blurred vision

Headache

Adynamic ileus

Dysgeusia

GI upset

Mild muscular incoordination

Syncope

Hypotension

Nystagmus

Diplopia

Flushing

Vertigo

Bradycardia

Urticaria

Skin eruptions

Conjunctivitis with nasal congestion

Anaphylactic reactions

Pruritus

Rash

Hemolysis (IV)

Increased Hgb and RBCs in urine (IV)

Seizures (IV)

Thrombophlebitis (IV)

Sloughing (IV)

Injection site pain (IV)

Black Box Warning

Contraindication / Caution

Contraindication

Intolerance to methocarbamol or any of its ingredients

Recognized or suspected renal dysfunction

Caution

Because methocarbamol is processed in the liver, use with caution in patients with impaired hepatic function. Methocarbamol has the potential for misuse and dependency, so use with caution in patients who have a history of drug addiction or dependence.

Those who are elderly or have poor renal function should use medication with caution as it may accumulate in these people and have negative side effects.

Usage with caution as it can raise the risk of sedation and respiratory depression in patients who are also taking other drugs that can depress the central nervous system, such as opioids or benzodiazepines. Those with a history of seizures should use methocarbamol with caution since it may lower the seizure threshold.

Pregnancy / Lactation

Pregnancy consideration:

Pregnancy category: C

Lactation: The excretion of drug into human milk is unknown 

Pregnancy Categories:     

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester.

Category B: There were lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.

Category N: There is no data available for the drug under this category.

Pharmacology

Pharmacology:

Methocarbamol is a centrally acting skeletal muscle relaxant that has both sedative and muscle relaxant effects. Although the precise mechanism of action is not entirely understood, it is thought to function by calming the central nervous system, which lowers muscular tone and spasm.

Pharmacodynamics:

In order to reduce muscular tone and spasm, methocarbamol, a centrally acting skeletal muscle relaxant, acts by depressing the central nervous system. Although the precise mechanism of action is not entirely understood, it is thought to operate by preventing the brain from receiving nerve impulses or pain signals.

The effects of methocarbamol are comparable to those of other sedative medicines like barbiturates and benzodiazepines since it primarily affects the spinal cord and subcortical regions of the brain. It does not have the same level of sedation as these medicines because it is not an opioid or narcotic.

Pharmacokinetics:

Absorption

Peak plasma concentrations of methocarbamol happen within 1-2 hours after oral dosing and are well absorbed. Food has no discernible impact on how well methocarbamol is absorbed.

Distribution

With a volume of distribution of around 1.3 L/kg, methocarbamol is broadly dispersed throughout the body. The primary protein to which methocarbamol is highly protein-bound is albumin, and it has a binding affinity that is comparable to other medicines that are also highly protein-bound

Metabolism

The liver extensively metabolises methocarbamol, mostly through glucuronidation and oxidation. Three-(hydroxyphenyl)-1,2-propanediol and three-(methoxyphenyl)-1,2-propanediol are the primary metabolites of methocarbamol. Age or renal impairment have no effect on the metabolism of methocarbamol.

Elimination and Excretion

Methocarbamol is mainly excreted unchanged in the urine, where it is removed at a 70–80% concentration. Methocarbamol has a 1.5–2-hour half-life of elimination, and renal excretion is the main route of clearance.

Adminstartion

Administration:

Methocarbamol is available as an oral tablet and an injectable solution

For oral tablets:

Methocarbamol is usually taken 3-4 times a day, with or without food.

For injectable solution:

Methocarbamol is usually administered as an intravenous infusion over 30 to 60 min

Patient Information Leaflet

Patient information leaflet

Generic Name: methocarbamol

Pronounced: [meth-oh-KAR-ba-mal]

Why do we use methenamine?

A drug called methocarbamol is used to treat illnesses including sprains, strains, and musculoskeletal disorders that result in muscle pain and discomfort. It is a skeletal muscle relaxant that functions by slowing down the central nervous system, which lowers muscular tone and reduces spasm.

Usually, no longer than a few weeks, methocarbamol is only given for short-term use. To treat muscle pain and stiffness, it is frequently used in conjunction with rest, physical therapy, and other methods.