8/8/2019 PharmTable03

1/1

revised 2009-08-14 Pharmacology Table 3: Skeletal Muscle Relaxants page 1 of 1

Drug Usual Dose1,2,3,4,5 Monthly Cost6* Comments 1,2,3,4, 5

Antispasmodics-Nonbenzodiazepine

Carisoprodol(Soma)Carisoprodol/Aspirin(SomaCompound)

350mg QID $$ Metabolized to meprobamate, an addictive sedative-hypnotic agent. Concern over abuse and dependence. Controlled substance insome states. Recommend to avoid. Evidence does not support use beyond 2-3 weeks. Withdrawal symptoms may occur withdiscontinuation.

Chlorzoxazone(Parafon Forte DSC)

250-750mg TID-QID $ Rare hepatotoxicity. May discolor urine orange or red.

Cyclobenzaprine(Flexeril, Fexmid)

5-10mg TIDMax: 60mg/day

$$ 5mg dose associated with lower incidence of somnolence with efficacy similar to 10mg dose. TCA derivative-contraindicated inpatients with cardiac conduction abnormalities. Should not be used within 14 days of MAOIs. Anticholinergic side effects. Avoid inelderly. Multiple drug-drug interactions (CYP3A4, 1A2, 2D6 substrate).

Cyclobenzaprine ER(Amrix)

15-30mg QD $$$$

Metaxalone(Skelaxin)

800mg TID-QID $$$$ Associated with hypersensitivity reaction. Use with caution in mild-mod hepatic disease. Avoid use in severe renal or hepaticdysfunction. Less CNS side effects, lack of abuse potential, and limited accumulation due to short half-life.

Methocarbamol(Robaxin)

1500mg QID x 72 hours,then 750mg QID

$$ Use with caution in renal and hepatic disease and in patients with history of seizure disorder. May discolor urine brown-black orgreen.

Orphenadrine(Norflex) 100mg BID $$$ Anticholinergic side effects-not recommended in elderl y. Do not discontinue abruptly.

Antispasticity

Baclofen(Lioresal)

5mg TIDMax: 80mg/d

$$$ Use with caution in renal dysfunction and in patients with history of seizure disorder. Do not discontinue abruptly.

Dantrolene(Dantrium)

25-100mg BID-QIDMax: 400mg/d

$$$$ Limited CNS effects. Black-box warning about dose-related fatal or nonfatal hepatitis; avoid in hepatic disease. Discontinue if nobenefit after 45 days.

Antispasmodic and Antispasticity

Diazepam(Valium)

2-10mg TID-QID $ Potential for abuse. Avoid in elderly and patients with renal or hepatic impairment. Mult iple drug-drug interactions (CYP3A4, 2C19).

Tizanidine(Zanaflex)

2-4mg every 6-8 hoursMax: 36mg/day

$$$$ May have gastroprotective effects. Frequent liver function monitoring recommended (may cause hepatotoxicity). May causehypotension and bradycardia. Adjust dose in renal insufficiency. Avoid concomitant use with ciprofloxacin and fluvoxamine, use

caution with other CYP1A2 inhibitors.*Cost based on generic when available for maximum daily dose. $: $100

References1. Max MB, Gilron IH. Antidepressants, Muscle Relaxants, and N-Methyl-D-Aspartate Receptor Antagonists. in Bonicas Management of Pain, 3 rd ed. Loeser JD, Butler SH, Chapman CR, Turk

DC. Eds. Lippincott, Williams, Wilkins: Philadelphia; 2001: 1710-1726.2. Toth PP, Urtis J. Commonly used muscle relaxant therapies for acute low back pain: a review of carisoprodol, cyclobenzaprine hydrochloride, and metaxalone. Clin Ther. 2004; 26: 1355-1367.3. van Tulder MW, Touray T, Furlan AD, Solway S, Bouter LM. Muscle relaxants for nonspecific low back pain: a systematic review within the framework of the Cochrane Collaboration. Spine

2003; 28: 1978-1992.4. Lexi-Comp (Lexi-Drugs, Comp + Specialties) [computer program]. Lexi-comp; May 29, 2009.5. See S, Ginzburg R. Skeletal muscle relaxants. Pharmacotherapy 2008;28:207-213.

6. www.drugstore.com accessed June 1, 2009.

VCU Chronic Nonmalignant Pain Curriculum 2009 Virginia Commonwealth Universi tyDo not redistr ibute. No derivative works are to be made.

http://www.drugstore.com/http://www.drugstore.com/