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Robaxin
methocarbamol
Adult Dosing .
Dosage forms: INJ: 100 mg per mL
Dosage Form Details
- [TAB form discontinued in US for this brand; see generic]
musculoskeletal pain, acute
- [PO route, initial treatment]
- Dose: 1500 mg PO qid x48-72h; Max: 8000 mg/day
- [PO route, maintenance treatment]
- Dose: 1000 mg PO qid; Alt: 750 mg PO q4h or 1500 mg PO tid
- [IM/IV route]
- Dose: 1000 mg IM/IV x1; Max: 3000 mg/day for up to 3 consecutive days; Info: may give additional 1000 mg IM/IV q8h prn if severe symptoms or unable to take PO; may repeat course after off treatment x48h
tetanus, adjunct tx
- [1000-2000 mg PO/NG/IV q6h]
- Start: 1000-2000 mg IV x1; Max: 3000 mg IV x1 for start dose; 24,000 mg/day PO/NG; Info: switch to PO/NG route when possible
renal dosing
- [PO route]
- renal impairment: not defined
- HD/PD: not defined
- [IM/IV route]
- renal impairment: contraindicated
- HD/PD: contraindicated
hepatic dosing
- [not defined]
Peds Dosing .
- Dosage forms: INJ: 100 mg per mL
Dosage Form Details
- [TAB form discontinued in US for this brand; see generic]
musculoskeletal pain, acute
- [initial treatment, 16 yo and older]
- Dose: 1500 mg PO qid x48-72h; Max: 8000 mg/day
- [maintenance treatment, 16 yo and older]
- Dose: 1000 mg PO qid; Alt: 750 mg PO q4h or 1500 mg PO tid
tetanus, adjunct tx
- [500 mg/m^2/dose IV q6h prn]
- Max: 1800 mg/m^2/total dose x3 consecutive days; Alt: 15 mg/kg/dose IV q6h prn
renal dosing
- [PO route]
- renal impairment: not defined
- HD/PD: not defined
- [IV route]
- renal impairment: contraindicated
- HD/PD: contraindicated
hepatic dosing
- [not defined]
Contraindications / Cautions .
- hypersensitivity to drug or ingredient
- renal impairment (IM or IV use)
- caution: CNS depressant use, concurrent
- caution: alcohol use, concurrent
- caution: elderly patients
- caution: seizure disorder (IM or IV use)
Drug Interactions .
Overview
methocarbamol
muscle relaxant
- anticholinergic effects
- CNS depression
- lowers seizure threshold
Avoid/Use Alternative
- aldesleukin
- amifampridine
- butalbital
- clonidine
- codeine
- doxylamine
- ethanol
- hydrocodone
- iohexol
- isocarboxazid
- kava
- kratom
- metaxalone
- metoclopramide
- midazolam
- oxybate
- phenelzine
- promethazine
- rivastigmine
- ropeginterferon alfa-2b
- thalidomide
- tranylcypromine
- trimethobenzamide
- zuranolone
Monitor/Modify Tx
- alfentanil
- alprazolam
- baclofen intrathecal
- buprenorphine
- bupropion
- butorphanol
- carbamazepine
- chlordiazepoxide
- chlorpromazine
- clobazam
- clonazepam
- clorazepate
- daridorexant
- desflurane
- dexmedetomidine
- dexmedetomidine injection
- diazepam
- dihydrocodeine
- droperidol
- esketamine
- estazolam
- eszopiclone
- ethanol (in some formulations)
- etomidate
- fentanyl
- fluphenazine
- flurazepam
- gabapentin
- gabapentin enacarbil
- hydromorphone
- hydroxyzine
- ifosfamide
- iopamidol
- isoflurane
- ketamine
- lemborexant
- levorphanol
- lorazepam
- meperidine
- methadone
- methohexital
- mirtazapine
- morphine
- nalbuphine
- nelarabine
- olanzapine
- oliceridine
- opicapone
- opium
- oxazepam
- oxybutynin
- oxycodone
- oxymorphone
- pentazocine
- pentobarbital
- perphenazine
- phenobarbital
- pregabalin
- primidone
- propofol
- quazepam
- remifentanil
- remimazolam
- sevoflurane
- sufentanil
- suvorexant
- tapentadol
- temazepam
- thioridazine
- thiothixene
- tramadol
- triazolam
- zaleplon
- ziconotide
- zolpidem
Caution Advised
- 5-HTP
- aceclidine ophthalmic
- acetazolamide
- allopurinol
- almotriptan
- amantadine
- amitriptyline
- amoxapine
- apomorphine
- apraclonidine ophthalmic
- aripiprazole bimonthly injection
- aripiprazole lauroxil
- aripiprazole monthly injection
- aripiprazole oral
- asenapine
- baclofen
- bethanechol
- botulinum toxin
- brexpiprazole
- brimonidine ophthalmic
- brimonidine topical
- brivaracetam
- bromocriptine
- brompheniramine
- buspirone
- busulfan
- cannabidiol
- cannabis
- carbinoxamine
- cariprazine
- carisoprodol
- cenobamate
- cetirizine
- cevimeline
- chamomile, German
- chlophedianol
- chlorambucil
- chlorpheniramine
- chlorzoxazone
- citalopram
- clemastine
- clomipramine
- clozapine
- cyclobenzaprine
- cyproheptadine
- dantrolene
- darifenacin
- desipramine
- desvenlafaxine
- deutetrabenazine
- dexbrompheniramine
- dexchlorpheniramine
- dichlorphenamide
- difelikefalin
- difenoxin
- dimenhydrinate
- diphenhydramine
- diphenoxylate
- domperidone
- donepezil
- doxepin
- doxepin topical
- dronabinol
- duloxetine
- efavirenz
- eletriptan
- entacapone
- entrectinib
- escitalopram
- eslicarbazepine acetate
- ethosuximide
- felbamate
- fenfluramine
- fesoterodine
- flibanserin
- fluoxetine
- fluvoxamine
- foslevodopa
- fosphenytoin
- frovatriptan
- galantamine
- ganaxolone
- glofitamab
- glycopyrrolate
- guanfacine
- haloperidol
- hydroxychloroquine
- hyoscyamine
- iloperidone
- imipramine
- lacosamide
- lamotrigine
- lasmiditan
- levetiracetam
- levocetirizine
- levodopa
- levomilnacipran
- linvoseltamab
- lofexidine
- loxapine
- lumateperone
- lurasidone
- magnesium citrate
- meclizine
- melatonin
- meprobamate
- methacholine inhaled
- methsuximide
- methyldopa
- metyrapone
- metyrosine
- milnacipran
- mitotane
- molindone
- mosunetuzumab
- mycophenolate mofetil
- naltrexone
- naratriptan
- nefazodone
- neostigmine
- nortriptyline
- orphenadrine
- oxcarbazepine
- paliperidone
- paroxetine
- passion flower
- perampanel
- pheniramine
- phenytoin
- pilocarpine
- pilocarpine ophthalmic
- pimozide
- polyethylene glycol
- polyethylene glycol/electrolytes
- pramipexole
- procarbazine
- prochlorperazine
- protriptyline
- pyridostigmine
- pyrilamine
- quetiapine
- ramelteon
- rasagiline
- repotrectinib
- risperidone
- rizatriptan
- ropinirole
- rotigotine transdermal
- rufinamide
- safinamide
- scopolamine
- selegiline
- selegiline transdermal
- selinexor
- sertraline
- sodium picosulfate
- solifenacin
- stiripentol
- sulfate bowel prep
- sumatriptan
- tasimelteon
- tetrabenazine
- thiotepa
- tiagabine
- tizanidine
- tolcapone
- tolterodine
- topiramate
- trazodone
- treosulfan
- trifluoperazine
- trihexyphenidyl
- trimipramine
- triprolidine
- trospium
- valbenazine
- valerian
- valproic acid
- venlafaxine
- vigabatrin
- vilazodone
- viloxazine
- ziprasidone
- zolmitriptan
- zonisamide
Adverse Reactions .
Serious Reactions
- hypersensitivity rxn
- anaphylaxis
- angioedema
- CNS depression
- seizures
- syncope
- bradycardia
- leukopenia
- thrombophlebitis
Common Reactions
- dizziness
- drowsiness
- lightheadedness
- insomnia
- confusion
- vertigo
- impaired coordination
- amnesia
- dyspepsia
- nausea
- vomiting
- jaundice
- urticaria
- pruritus
- rash
- conjunctivitis
- blurred vision
- diplopia
- nystagmus
- headache
- fever
- flushing
- hypotension
- metallic taste
- nasal congestion
Safety/Monitoring .
Monitoring Parameters
PO Route: no routine tests recommended
IM/IV Route: Cr at baseline
Polyethylene Glycol 300 Content
INJ form contains 0.5 mL polyethylene glycol 300 per mL; may increase pre-existing acidosis and urea retention in patients with renal impairment, especially at higher than recommended doses
Look/Sound-Alike Drug Names
Robaxin confused with: Reglan; Relafen; ribavirin; Rocephin; Skelaxin
methocarbamol confused with: metFORMIN; metoclopramide; metroNIDAZOLE; nabumetone
Pregnancy/Lactation .
Pregnancy
Clinical Summary
weigh risk/benefit during pregnancy; possible risk of teratogenicity based on conflicting human data
Lactation
Clinical Summary
weigh risk/benefit while breastfeeding; no human data available to assess risk of infant harm, though possible drug excretion into milk based on drug properties; no human data available to assess effects on milk production
Pharmacology .
Metabolism: liver; CYP450: unknown
Excretion: urine (minimally unchanged); Half-life: 1-2h
Subclass: Muscle Relaxants
Mechanism of Action
exact mechanism of action unknown; depresses CNS activity (centrally-acting muscle relaxant)
Formulary .
No Formulary Selected
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