Methocarbamol


Generic Medicine Info
Indications and Dosage
Intramuscular, Intravenous
Painful muscle spasm associated with acute musculoskeletal conditions
Adult: As an adjunct, for short-term symptomatic treatment: Dose is based on the severity of the condition and therapeutic response. Initially: 1,000 mg as a single dose. In severe cases or when oral therapy is not feasible: May give additional 1,000 mg 8 hourly; Max of 3,000 mg daily for no more than 3 consecutive days. If condition persists, may repeat course of treatment after a drug-free interval of 48 hours. Doses may be given via slow IV inj (Max rate of 300 mg/min), IV infusion; or deep IM inj (Max of 500 mg/gluteal region). Dosing recommendations may vary among individual products and between countries (refer to specific product guidelines).

Intravenous
Tetanus
Adult: As an adjunct, for management: Initially, 1,000-2,000 mg via direct IV inj. May give additional 1,000-2,000 mg via IV infusion, to give a total initial dose of up to 3,000 mg. Repeat dosage 6 hourly until nasogastric tube can be inserted. Treatment guidelines may vary among individual products and between countries (refer to specific product guidelines).
Child: As an adjunct, for management: Initially, 15 mg/kg or 500 mg/m2; may repeat 6 hourly if needed. Max total: 1,800 mg/m2 for 3 consecutive days. Treatment guidelines may vary among individual products and between countries (refer to specific product guidelines).

Oral
Painful muscle spasm associated with acute musculoskeletal conditions
Adult: As an adjunct, for short-term symptomatic treatment: Initially, 1,500 mg 4 times daily for 2-3 days (may give up to 8,000 mg daily in severe conditions). Usual maintenance dose: 2,250-4,500 mg daily in 3-4 divided doses. Dosing recommendations may vary among individual products and between countries (refer to specific product guidelines).
Elderly: Dose reduction may be required.
Renal Impairment
Intravenous/Intramuscular:
Painful muscle spasm associated with acute musculoskeletal conditions:
Contraindicated.

Intravenous:
Tetanus:
Contraindicated.
Administration
May be taken with or without food. May be taken w/ meals to reduce GI discomfort.
Reconstitution
IV infusion: Dilute with appropriate amount of NaCl 0.9% inj or 5% dextrose inj to prepare the desired concentration. Refer to specific product guidelines.
Contraindications
Brain damage; epilepsy; myasthenia gravis, coma or pre-coma states. Renal impairment (inj).
Special Precautions
Patient must be in a recumbent position during and for at least 10-15 minutes after administration (IV). Renal (oral) and hepatic impairment. Children (when used in tetanus) and elderly. Pregnancy and lactation.
Adverse Reactions
Significant: CNS depression.
Blood and lymphatic system disorders: Leucopenia.
Cardiac disorders: Bradycardia.
Ear and labyrinth disorders: Vertigo.
Eye disorders: Blurred vision, nystagmus, diplopia, conjunctivitis.
Gastrointestinal disorders: Dyspepsia, nausea, vomiting, metallic taste.
General disorders and administration site conditions: Fever; inj site pain and sloughing (IV/IM).
Hepatobiliary disorders: Jaundice (including cholestatic jaundice).
Immune system disorders: Hypersensitivity reactions (e.g. anaphylaxis, angioedema).
Nervous system disorders: Headache, seizures, mild muscular incoordination, dizziness, drowsiness.
Psychiatric disorders: Confusion, amnesia, insomnia.
Respiratory, thoracic and mediastinal disorders: Nasal congestion.
Skin and subcutaneous tissue disorders: Pruritus, rash, urticaria.
Vascular disorders: Flushing, hypotension, syncope, thrombophlebitis.
IM/IV/Parenteral/PO: C
Patient Counseling Information
This drug may cause dizziness or drowsiness, if affected, do not drive or operate machinery.
Monitoring Parameters
Monitor for signs of bradycardia, hypotension; extravasation (IV).
Overdosage
Symptoms: Nausea, drowsiness, blurred vision, hypotension, seizures, coma. Management: Symptomatic and supportive treatment. Maintain adequate airway, monitor vital signs and urine output, administer IV fluids if needed.
Drug Interactions
May potentiate the effects of other CNS depressants and stimulants (e.g. barbiturates, anaesthetics, appetite suppressants), anticholinergics (e.g. atropine) and certain psychotropic drugs. May suppress the effect of pyridostigmine bromide.
Food Interaction
May enhance the CNS depressant effect of alcohol.
Lab Interference
May produce a colour interference in certain screening tests for 5-hydroxyindoleacetic acid (5-HIAA) using nitrosonaphthol reagent and in screening tests for urinary vanillylmandelic acid (VMA) using the Gitlow method.
Action
Description:
Mechanism of Action: Methocarbamol is a carbamate derivative of guaifenesin that relaxes skeletal muscle by general CNS depression.
Onset: Approx 30 minutes (oral).
Pharmacokinetics:
Absorption: Rapidly and almost completely absorbed from the gastrointestinal tract. Time to peak plasma concentration: 1-2 hours (oral).
Distribution: Plasma protein binding: 46-50%.
Metabolism: Metabolised in the liver via dealkylation and hydroxylation.
Excretion: Via urine (mainly as metabolites). Elimination half-life: 1-2 hours.
Chemical Structure

Chemical Structure Image
Methocarbamol

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 4107, Methocarbamol. https://pubchem.ncbi.nlm.nih.gov/compound/Methocarbamol. Accessed Nov. 26, 2021.

Storage
Tab: Store between 20-25°C. Intact vial: Store between 15-30°C.
MIMS Class
Muscle Relaxants
ATC Classification
M03BA03 - methocarbamol ; Belongs to the class of carbamic esters. Used as centrally-acting muscle relaxants.
References
Anon. Methocarbamol. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 15/10/2021.

Anon. Methocarbamol. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 15/09/2021.

Buckingham R (ed). Methocarbamol. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 15/09/2021.

Joint Formulary Committee. Methocarbamol. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 15/09/2021.

Methocarbamol 1,500 mg Film-Coated Tablets (Neuraxpharm UK Limited). MHRA. https://products.mhra.gov.uk. Accessed 15/09/2021.

Methocarbamol 750 mg Film-Coated Tablets (Activase Pharmaceuticals Ltd.). MHRA. https://products.mhra.gov.uk. Accessed 15/09/2021.

Methocarbamol Injection (Somerset Therapeutics, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 15/09/2021.

Methocarbamol Tablet, Coated (Burel Pharmaceuticals, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 15/09/2021.

Disclaimer: This information is independently developed by MIMS based on Methocarbamol from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2024 MIMS. All rights reserved. Powered by MIMS.com
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