Home / Medicine / Robaxin

Robaxin

Travellers familiar with Robaxin from one English-speaking market are unlikely to encounter the same brand under that name in many others — it is registered in only six countries. Those markets are Australia, the United States, South Africa, the United Kingdom, Canada, and Spain, a footprint that crosses several continents but remains narrow compared with the broader availability of its active ingredient.

The active ingredient in Robaxin is methocarbamol, a centrally acting skeletal muscle relaxant. It is used in the management of muscle cramp and, as listed in the structured data on this page, convulsions associated with musculoskeletal conditions. Muscle relaxants in this category are generally prescribed as part of a short-term approach to musculoskeletal discomfort, often alongside other measures directed at the underlying cause. The complete list of registered indications recognised in each country where Robaxin is sold appears in the structured section further down this page.

Because Robaxin is registered in only a small number of markets, a traveller arriving in a country outside that list will probably not see this brand on the pharmacy shelf. Methocarbamol itself, however, circulates internationally under other brand names in several regions, and other skeletal muscle relaxants — different molecules within the same broad therapeutic category — are also used in many markets where Robaxin is not directly available. A local pharmacist is well placed to identify what is offered regionally and how prescription rules apply.

Skeletal muscle relaxants are not all interchangeable, and the choice of molecule typically reflects the prescriber's assessment of the patient's situation. Anyone currently using Robaxin, or trying to identify a comparable product while abroad, should treat any change as a clinical question for a healthcare provider rather than a self-directed substitution at the counter.

Countries
Australia Canada South Africa Spain United Kingdom USA
Diseases
Convulsions Muscle cramp
Ingredients
Methocarbamol

Drugs with the same active ingredients

Methocarbamol ilium Carbafen Methoxacet-c1/8 Methoxisal-c Methoxacet-c1/8 (acetaminophen,codeine,methocarbamol) Methoxisal-c (aspirin,codeine,methocarbamol) Methoxisal-c 1 / 2 Robaxacet-8 Robaxisal-c Robaxacet-8 (acetaminophen,codeine,methocarbamol) Robaxisal-c (aspirin,codeine,methocarbamol) Robaxisal c-1 / 2 Spasmhalt-8 Myomethol Beseroldos Beseroldos (acetaminophen,methocarbamol) Methocarb 500-ezs Methocarbamol Robaxin-v Methocarbamol recordati

Overdose

Limited information is available on the acute toxicity of methocarbamol. Overdose of methocarbamol is frequently in conjunction with alcohol or other CNS depressants and includes the following symptoms: nausea, drowsiness, blurred vision, hypotension, seizures and coma. One adult survived the deliberate ingestion of 22 to 30 grams of methocarbamol without serious toxicity. Another adult survived a dose of 30 to 50 grams. The principal symptom in both cases was extreme drowsiness. Treatment was symptomatic and recovery was uneventful. However, there have been cases of fatal overdose.

Management of overdose includes symptomatic and supportive treatment. Supportive measures include maintenance of an adequate airway, monitoring urinary output and vital signs, and administration of intravenous fluids if necessary. The usefulness of haemodialysis in managing overdose is unknown.

Shelf life

Amber glass bottles: 60 months

Blister packs: 24 months

HDPE bottles with HDPE child resistant caps: 60 months

Contraindications

Coma or pre-coma states. Known brain damage or epilepsy. Myasthenia gravis.

Incompatibilities

Not applicable.

List of excipients

Alginic acid, maize starch, povidone, sodium lauryl sulphate, gelatin, magnesium stearate, talc, sepifilm 002, sepisperse white AP 7001, potable mains water.

Pharmaceutical form

Film-coated tablet.

Undesirable effects

Adverse reactions reported coincident with the administration of methocarbamol include

Body as a whole: Angioneurotic oedema, anaphylactic reaction, fever, headache.

Cardiovascular system: Bradycardia, flushing, hypotension, syncope.

Digestive system: Dyspepsia, jaundice (including cholestatic jaundice), nausea and vomiting.

Blood and lymphatic system: Leucopenia.

Nervous system: Restlessness, anxiety, tremor, amnesia, confusion, diplopia, dizziness or light-headedness, vertigo, drowsiness, insomnia, mild muscular incoordination, nystagmus, seizures (including grand mal).

Skin and special senses: Blurred vision, conjunctivitis with nasal congestion, metallic taste, pruritus, rash, urticaria.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme, Website: www.mhra.gov.uk/yellowcard.

Preclinical safety data

Nothing of note to the prescriber.

Therapeutic indications

As a short-term adjunct to the symptomatic treatment of acute musculoskeletal disorders associated with painful muscle spasms.

Pharmacotherapeutic group

Muscle relaxants, centrally acting agents; Carbamic acid esters, ATC code: M03BA03.

Pharmacodynamic properties

Pharmacotherapeutic group: Muscle relaxants, centrally acting agents; Carbamic acid esters, ATC code: M03BA03.

Robaxin-750 is used as a short-term adjunct to the symptomatic treatment of acute musculoskeletal disorders associated with painful muscle spasms.

The mechanism of action of methocarbamol in humans has not been established, but may be due to general central nervous system depression. It has no direct action on the contractile mechanism of striated muscle, the motor end plate or the nerve fibre.

Pharmacokinetic properties

Methocarbamol is absorbed from the gastro-intestinal tract and produces peak plasma concentrations after about 1-3 hours. Its activity derives from the intact molecule and only a small proportion is converted to guaiphenesin.

Renally impaired

The clearance of methocarbamol in renally-impaired patients on maintenance haemodialysis was reduced about 40% compared to a normal population, although the mean elimination half-life in these two groups was similar (1.2 versus 1.1 hours, respectively).

Hepatically impaired

In patients with cirrhosis secondary to alcohol abuse, the mean total clearance of methocarbamol was reduced approximately 70% compared to a normal population (11.9 L/hr), and the mean elimination half-life was extended to approximately 3.4 hours. The fraction of methocarbamol bound to plasma proteins was decreased to approximately 40 to 45% compared to 46 to 50% in an age- and weight-matched normal population.

Date of revision of the text

31st July 2017

Name of the medicinal product

Robaxin-750, 750 mg film-coated tablets

Marketing authorisation holder

Almirall, S.A.

Ronda General Mitre, 151

08022 Barcelona

Spain

Special precautions for storage

No special storage conditions are necessary.

Nature and contents of container

Amber glass bottles containing 500, 100 or 6 tablets.

Blister packs containing 56 or 8 tablets.

HDPE bottles with HDPE child resistant caps containing 100 tablets.

Marketing authorisation number(s)

PL 16973/0015

Fertility, pregnancy and lactation

Fertility

Animal reproductive studies have not been conducted with methocarbamol. It is also not known whether methocarbamol can cause foetal harm when administered to a pregnant woman or can affect reproduction capacity.

Pregnancy

Safe use of methocarbamol has not been established with regard to possible adverse effects upon foetal development. There have been very rare reports of foetal and congenital abnormalities following in utero exposure to methocarbamol. Therefore methocarbamol tablets should not be used in women who are or may become pregnant and particularly during early pregnancy unless in the judgement of the physician the potential benefits outweigh the possible hazards.

Breastfeeding

Methocarbamol and/or its metabolites are excreted in the milk of dogs: however, it is not known whether methocarbamol or its metabolites are excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Robaxin-750 is administered to a nursing woman.

Qualitative and quantitative composition

Each white, capsule-shaped tablet contains 750 mg methocarbamol.

Special warnings and precautions for use

Robaxin-750 should be used with caution in patients with renal and hepatic insufficiency.

Effects on ability to drive and use machines

This product may cause drowsiness and patients receiving it should not drive nor operate machinery unless their physical and mental capabilities remain unaffected - especially if other medication capable of causing drowsiness is also being taken.

Dosage (Posology) and method of administration

For oral use.

Posology

Adults: The usual dose is 2 tablets four times daily but therapeutic response has been achieved with doses as low as 1 tablet three times daily.

Elderly: Half the maximum dose or less may be sufficient to produce a therapeutic response.

Paediatric population

Not recommended.

Hepatically impaired

In patients with chronic hepatic disease the elimination half-life may be prolonged. Therefore, consideration should be given to increasing the dose interval.

Special precautions for disposal and other handling

None

Date of first authorisation/renewal of the authorisation

26th August 2003

Interaction with other medicinal products and other forms of interaction

This product may potentiate the effects of other central nervous system depressants and stimulants including alcohol, barbiturates, anaesthetics and appetite suppressants. The effects of anticholinergics, e.g. atropine and some psychotropic drugs, may be potentiated by methocarbamol. Methocarbamol may inhibit the effect of pyridostigmine bromide. Therefore methocarbamol should be used with caution in patients with myasthenia gravis receiving anticholinesterase agents. Little is known about the possibility of interactions with other drugs.

Methocarbamol may cause colour interference in certain screening tests for 5-hydroxyindolacetic acid (5-HIAA) using nitrosoaphthol reagent and in screening tests for urinary vanillymandelic acid (VMA) using the Gitlow method.

Frequently asked questions

What conditions does Robaxin treat?

Robaxin is prescribed in the management of muscle cramp and convulsions associated with musculoskeletal conditions, as listed in the structured indication block on this page. Its active ingredient belongs to the skeletal muscle relaxant category, a group of medications generally used as part of a short-term approach to musculoskeletal discomfort. The full list of registered uses recognised by national regulators in each market where Robaxin is sold is shown below this introduction.

Which active substance is in Robaxin?

Robaxin contains methocarbamol, a centrally acting skeletal muscle relaxant. The same active ingredient is marketed in various countries under several different brand names, particularly where the original brand is not registered. Methocarbamol-containing products and other muscle relaxants in the broader category are part of routine pharmacy stock in many markets, even where the Robaxin brand itself is not directly available.

In how many countries is Robaxin available?

Robaxin is registered in six countries: Australia, the United States, South Africa, the United Kingdom, Canada, and Spain. Outside this list the specific brand is generally not encountered, although methocarbamol and other skeletal muscle relaxants are available in many other markets under different names. If your country is not represented here, a local pharmacist can confirm what comparable products are stocked regionally.

Are there other medications with the same active ingredient as Robaxin?

Methocarbamol is sold under several brand names internationally, and other skeletal muscle relaxants — different molecules in the same broad therapeutic category — are widely used in markets where Robaxin itself is not registered. These are not freely interchangeable, since molecules within a category differ in their profiles. To identify a regional product, search the active ingredient on Pill2Trip or ask a pharmacist in your country.

Is Robaxin a prescription medication?

Robaxin is a prescription medication in the markets where it is registered, although the specific rules around dispensing skeletal muscle relaxants vary from country to country. Patients travelling or relocating between jurisdictions should not assume that a familiar product will be supplied on the same basis abroad. Any decision about starting, continuing, or substituting a muscle relaxant belongs with a healthcare provider familiar with the patient's situation.

Robaxin

Available in 6 countries