Search
methocarbamol (Robaxin)
Methocarbamol. Tradename: Robaxin.
Indications:
1) muscle relaxant*
2) treatment of muscle spasms associated with acute, painful musculoskeletal conditions
- tetanus [4]
* on list of medications to avoid; no proven efficacy [5]
Dosage:
1) 1000-1500 mg PO QID
2) maintenance 500-1000 mg QID
3) 1 g IM/IV* every 8 hours (infusion rate < 3 mL/min)
Tabs: 500 & 750 mg.
Injection: 100 mg/mL (10 mL)
* NOT recommend for SC injection
Pharmacokinetics:
1) excreted as a metabolite mainly in the urine with a small amount in the feces
2) 1/2life 1-2 hours
Adverse effects:
1) common (> 10%)
- drowsiness, dizziness, lightheadedness
2) less common (1-10%)
- nausea/vomiting, facial flushing, nystagmus, allergic dermatitis, bradycardia, nasal congestion
3) uncommon (< 1%)
- pain at site of injection, leukopenia, convulsions, fainting, thrombophlebitis, blurred vision, renal impairment
4) other
- urticaria
- headache
- may color urine brown, black or green
Mechanism of action:
1) mechanism not fully established
2) may cause general CNS depression
3) no direct action on contractile mechanism of striated muscle, motor endplates or nerve endplates
4) does NOT directly relax tense skeletal muscles
General
skeletal muscle relaxant (tranquilizer)
Properties
MISC-INFO: elimination route LIVER
KIDNEY
1/2life 2-2 HOURS
pregnancy-category C
safety in lactation +
Database Correlations
PUBCHEM cid=4107
References
- The Pharmacological Basis of Therapeutics, 9th ed.
Gilman et al, eds. Permagon Press/McGraw Hill, 1996
- Drug Information & Medication Formulary, Veterans Affairs,
Central California Health Care System, 1st ed., Ravnan et al
eds, 1998
- Kaiser Permanente Northern California Regional Drug
Formulary, 1998
- Deprecated Reference
- Therapeutics Letter #108. Therapeutics Initiative
Drugs to Avoid.
http://www.ti.ubc.ca/2018/01/04/108-drugs-avoid/
Component-of
aspirin/methocarbamol (Robaxisal)