THERAPEUTICS

Brands

• Skelaxin

Generic?

• Yes

Class

• Muscle relaxant

Commonly Prescribed for

(FDA approved in bold)

• Musculoskeletal conditions (adjunct to rest and physical therapy for relief of acute pain)

• Spasticity

How the Drug Works

• Unclear but might be related to general CNS depression effect

How Long Until It Works

• Pain: hours

If It Works

• Slowly titrate to most effective tolerated dose

If It Doesn't Work

• Increase to highest tolerated dose and consider alternative treatments

Best Augmenting Combos for Partial Response or Treatment-Resistance

• Use other centrally acting muscle relaxants with caution due to potential CNS depressant effect

• Can combine with NSAIDs for acute pain

Tests

• None

ADVERSE EFFECTS (AEs)

How the Drug Causes AEs

• CNS depression

Notable AEs

• Nausea, drowsiness, dizziness, headache, irritability, rash

Life-Threatening or Dangerous AEs

• Hemolytic anemia and leukopenia have been reported

Weight Gain

• Unusual

Sedation

• Common

What to Do About AEs

• Lower the dose or discontinue drug

Best Augmenting Agents to Reduce AEs

• Most AEs cannot be reduced by an augmenting agent

DOSING AND USE

Usual Dosage Range

• 800–3200mg/day

Dosage Forms

• Tablets: 800mg

How to Dose

• In children over 12 and adults, give 400–800mg 3–4 times daily

Dosing Tips

• Taking with food increases CNS depression

Overdose

• Overdose with alcohol can lead to death. Reports of serotonin syndrome. Treat with gastric lavage and supportive therapy

Long-Term Use

• Not well studied

Habit Forming

• No

How to Stop

• Taper not required

Pharmacokinetics

• Peak effect at 3 hours and half-life 9 hours. Hepatic metabolism to metabolites excreted in urine

Drug Interactions

• May enhance effect of other CNS depressants, such as alcohol, barbiturates, or benzodiazepines

Other Warnings/ Precautions

• May impair mental or physical abilities when driving or performing hazardous tasks