Table 5.

Muscle relaxants

Medication	Indication	Dosage Range	Clinical Pearls
Antispasticity Agents
Baclofen   (Lioresal)	Spasticity	5 mg 2–3 times/d for Max 80 mg/d	Black box warning: Caution abrupt discontinuation, risk of withdrawal No dose adjustments required for renal or hepatic dysfunction
Dantrolene   (Dantrium)	Spasticity	Start 25 mg (25–100 mg)  4 times a day	Black bock warning: risk for hepatotoxicity with chronic use, monitor hepatic function May cause sun sensitivity
Tizanidine   (Zanaflex)	Spasticity	Initial 2 mg ≤3 times/d Titrate in 2-4 mg  increments per dose  over 1–4 d Max 36 mg/d (single doses  of >16 mg have not  been studied)	Avoid rapid discontinuation: gradually taper by 2-4 mg/d Use with caution in older adults who have decreased clearance Monitor liver function Monitor QT interval with chronic use
Antispasmodic agents
Carisoprodol   (Soma)	Acute  musculoskeletal  pain	250–350 mg 3 times/d	Controlled substance C-IV has been subject to abuse, dependence, withdrawal, misuse, and diversion Active metabolites with barbiturate effects increasing somnolence and risk of falls for older adults Caution orthostatic hypotension Limit use to 2–3 wk
Cyclobenzaprine   (Amrix; Flexeril   DSC)	Musculoskeletal  pain	IR tablet 5 mg 3 times/d Max 10 mg 3 times/d Extended-release tables –  not recommended for  geriatric patients	Caution anticholinergic effects/burden Not recommended in mild to severe hepatic impairment Do not use within 14 d of MAOIs
Metaxolone   (Skelaxin)	Musculoskeletal  pain	800 mg 3–4 times/d	Absorption is increased when taken with food Contraindicated in severe hepatic and renal dysfunction, monitor liver function
Methocarbamol   (Robaxin)	Musculoskeletal  pain	750–1000 mg orally every  4 hours, up to 4 g/day  for maintenance Max 4 g/d	Use lower doses at initiation of drug especially with geriatric patients, titrate as clinically indicated No dose adjustments required for renal or hepatic dysfunction Drug may change color of urine to brown, black, or green

Abbreviations: IR, immediate release; MAOI, monoamine oxidase inhibitors.