1.1. Adults

The skeletal muscle relaxants (SMRs), carisoprodol, chlorzoxazone, cyclobenzaprine, methocarbamol, metaxalone, and orphenadrine, are FDA-approved for short-term use to manage discomfort associated with acute, painful musculoskeletal conditions such as strains, sprains, and other muscle injuries1-10. These agents should be used as an adjunct to non-pharmacologic treatments, including rest and physical therapy. Baclofen is FDA approved to alleviate signs and symptoms of spasticity resulting from multiple sclerosis, particularly for the relief of flexor spasms and concomitant pain, clonus, and muscular rigidity. Baclofen may also be useful in patients with spinal cord injuries and other spinal cord diseases1,2,11-14. Tizanidine is FDA approved for the management of spasticity, and dantrolene is FDA approved for managing spasticity due to upper motor neuron disorders (e.g., spinal cord injury, cerebral palsy, multiple sclerosis, or stroke)1,2,15,16. Maximum recommended dosages for SMRs are summarized in Table 1. Dosages exceeding these recommendations will be reviewed.

Table 1. Skeletal Muscle Relaxant Maximum Recommended Dosages (Adults): Monotherapy1-16
Drug Name Dosage Form/Strength Treatment Indication Maximum Recommended Dosage
baclofen (generic, Lyvispah®, Ozobax®, Fleqsuvy®) 5 mg, 10 mg, 20 mg tablets (generic); 5 mg, 10 mg, 20 mg oral granules (Lyvispah®); 5 mg/ 5 mL oral solution (Ozobax®, generic); 5 mg/mL oral suspension (Fleqsuvy®) spasticity 80 mg/day, in divided doses
carisoprodol (Soma®, generic) 250 mg, 350 mg tablets muscle spasm 1400 mg/day, in divided doses
chlorzoxazone (generic) 250 mg, 375 mg, 500 mg tablets, 750 mg tablets muscle spasm 3000 mg/day, in divided doses
chlorzoxazone (Lorzone®) 375 mg, 750 mg tablets muscle spasm 3000 mg/day, in divided doses
cyclobenzaprine tablet (Fexmid®, generic) 5 mg, 7.5 mg (Fexmid®), 10 mg tablets muscle spasm 30 mg/day, in divided doses
cyclobenzaprine capsule, extended-release (Amrix®, generic) 15 mg, 30 mg capsules muscle spasm 30 mg/day
dantrolene (Dantrium®, generic) 25 mg, 50 mg, 100 mg capsules spasticity 400 mg/day, in divided doses
metaxalone (Skelaxin®, generic) 400 mg, 800 mg tablets muscle spasm 3200 mg/day, in divided doses
methocarbamol (Robaxin®, generic) 500 mg, 750 mg tablets muscle spasm 8 g/day, in divided doses
orphenadrine ER (generic) 100 mg extended-release tablet muscle spasm 200 mg/day, in divided doses
tizanidine 2 mg, 4 mg tablets (Zanaflex®, generic); 2 mg, 4 mg, 6 mg capsules (Zanaflex®, generic) spasticity 36 mg/day, in divided doses
Table 2. Skeletal Muscle Relaxant Maximum Recommended Dosages (Adults): Combination Therapy1,2,17,18
Drug Name Dosage Form/Strength Treatment Indication Maximum Recommended Dosage 
carisoprodol/ ASA/codeine (generic) 200 mg/325 mg/16 mg tablets acute pain associated with musculoskeletal conditions 400 mg/650 mg/32 mg (2 tablets) four times daily
orphenadrine/ ASA/ caffeine (Norgesic Forte®, generic) 25 mg/385 mg/30 mg, 50 mg/770 mg/60 mg tablets Mild to moderate pain of acute musculoskeletal disorders 200 mg/3080 mg/240 mg daily

Legend:

  • ASA - aspirin