Baclofen

Administration

  • Type: Muscle relaxant/anti-spasmodic
  • Dosage Forms: tablet, intrathecal solution, preservative free intrathecal solution
  • Dosage Strengths: tablet: 10, 20mg; intrathecal solution: 50, 500mcg/mL; preservative free intrathecal solution: 500, 1000, 2000 mcg/mL
  • Routes of Administration: oral, intrathecal
  • Common Trade Names: Lioresal, Gablofen

Adult Dosing

  • 5-20mg PO 3-4 times/day
  • maintenance intrathecal rate after titration: 22 to 1400 mcg/day

Pediatric Dosing

  • 2-7yo: 10 to 15 mg/day PO in 2-3 divided doses, titrate to max 40mg/day in 3-4 divided doses
  • >7 yo: 10 to 15 mg/day PO in 2-3 divided doses, titrate to max 60mg/day in 3-4 divided doses
  • <12 yo: maintenance intrathecal rate after titration- 24 to 1199 mcg/day

Special Populations

Renal Dosing

  • CrCl 50-80 mL/min: reduce dose by 1/3
  • CrCl 30-50 mL/min: reduce dose by 1/2
  • CrCl <30 mL/min: reduce dose by 2/3
  • If HD, use intrathecal with caution, likely reduce dose

Hepatic Dosing

  • No adjustment

Contraindications

  • Allergy to class/drug

Adverse Reactions

Serious

  • GI bleed
  • Coma
  • Seizure
  • Aseptic meningitis
  • Pneumonia
  • Withdrawal

Common

  • Hypotension
  • Nausea/vomiting, constipation
  • Dizziness, somnolence, asthenia, poor muscle tone
  • Urinary complications

Pharmacology

  • Half-life: 5 hours (oral), 1.5-4 hours (intrathecal)
  • Metabolism: Hepatic (15%)
  • Excretion: Mostly renal

Mechanism of Action

  • GABA agonist

Comments

See Also

References

  • Abarbanel J, Herishanu Y, Frisher S, “Encephalopathy Associated With Baclofen,” Ann Neurol, 1985, 17(6):617-8. [PubMed 4026235]
  • Addolorato G, Leggio L, Ferrulli A, et al. Effectiveness and safety of baclofen for maintenance of alcohol abstinence in alcohol-dependent patients with liver cirrhosis: randomized, double-blind controlled study. Lancet. 2007;370:1915-1922. [PubMed 18068515]
  • Agarwal SK, Kriel RL, Cloyd JC, et al. A pilot study assessing pharmacokinetics and tolerability of oral and intravenous baclofen in healthy adult volunteers. J Child Neurol. 2015;30(1):37-41. [PubMed 25028414]10.1177/0883073814535504
  • Aisen ML, Dietz M, McDowell F, Kutt H. Baclofen toxicity in a patient with subclinical renal insufficiency. Arch Phys Med Rehabil. 1994;75(1):109-111. [PubMed 8291951]
  • Albright AL, “Baclofen in Treatment of Cerebral Palsy,” J Child Neurol, 1996, 11(2):77-83. [PubMed 8881981]
  • Anderson PO, Sauberan JB. Modeling drug passage into human milk. Clin Pharmacol Ther. 2016;100(1):42-52. [PubMed 27060684]
  • ASHP. Standardize 4 Safety Initiative Compounded Oral Liquid Version 1.01. July 2017. https://www.ashp.org/-/media/assets/pharmacy-practice/s4s/docs/s4s-ashp-oral-compound-liquids.ashx?la=en&hash=4C2E4F370B665C028981B61F6210335AD5D0D1D6.
  • Averbuch-Heller L, Tusa RJ, Fuhry L, et al. A double-blind controlled study of gabapentin and baclofen as treatment for acquired nystagmus. Ann Neurol. 1997;41(6):818-825. [PubMed 9189045]
  • Baclofen tablet [prescribing information]. Pulaski, TN: AvKare Inc; April 2014.
  • Brunton LL, Chabner BA, Knollmann BC, eds. Goodman & Gilman's The Pharmacological Basis of Therapeutics. 12th ed. New York, NY: McGraw-Hill Medical; 2011.