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baclofen (Lioresal)

Tradename: Lioresal. Indications: 1) relief of signs & symptoms of muscle spasm a) multiple sclerosis b) spinal cord injury c) spinal stenosis 2) refractory GERD Contraindications: Caution: elderly patients are sensitive to bacolfen Dosage: Start 5 mg PO TID, max 80 mg/day. Tabs: 10 & 20 mg. Dosage adjustment in renal failure: - may be necessary to adjust in renal failure Adverse effects: 1) common (> 10%) - drowsiness, vertigo, dizziness, psychiatric disturbances, insomnia, slurred speech (rare according to ref 2), ataxia, hypotonia, muscle weakness 2) less common (1-10%) - hypotension, fatigue, confusion, headache, rash, nausea, constipation, urinary frequency 3) uncommon (< 1%) - palpitations, chest pain, syncope, euphoria, excitement, depression, hallucinations, dry mouth, anorexia, taste disorder, abdominal pain, vomiting, diarrhea, enuresis,urinary retention, dysuria, impotence, nocturia, hematuria, paresthesias, dyspnea 4) other [2] a) blurred vision (rare) b) seizures (rare); seizures may occur during withdrawal [4] c) symptoms of withdrawal with abrupt discontinuation [6] - hallucinations, delusions, confusion, agitation, anxiety, insomnia, altered consciousness, hyperthermia, spasticity, tachycardia, seizures - use for over one month is risk factor for delirium d) use in patients with renal failure may result in encephalopathy [8] e) baclofen is associated with higher incidences of injury & delirium compared to tizanidine when used for musculoskeletal pain [9] f) baclofen is associated with higher 30-day incidence & 1-year persistence of encephalopathy vs tizanidine or cyclobenzaprine (RR= 2.3 (30-day)) [10] 5) risk of falls: baclofen, cyclobenzaprine > tizanidine - risk of fracture: baclofen, cyclobenzaprine = tizanidine [11] Drug interactions: - CNS depressants Laboratory: - baclofen in specimen - baclofen in hair - baclofen in body fluid - baclofen in blood - baclofen in serum/plasma - baclofen in urine Mechanism of action: 1) inhibits both monosynaptic & polysynaptic reflexes at the level of the spinal cord 2) effects may be mediated by hyperpolarization of afferent terminals 3) derivative of GABA & may stimulate GABA-B receptor 4) inhibits transient relaxation of lower esophageal sphincter [5]

Related

gamma-aminobutyric acid (GABA) B receptor gamma-aminobutyric acid (GABA, Gammalone, Mielomade)

General

amine antispasmodic carboxylate skeletal muscle relaxant (tranquilizer)

Properties

MISC-INFO: elimination route KIDNEY 1/2life 2.5-4 HOURS pregnancy-category C safety in lactation ?

Database Correlations

PUBCHEM correlations

References

  1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
  2. Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
  3. Kaiser Permanente Northern California Regional Drug Formulary, 1998
  4. Medications Can Cause Seizures Prescriber's Letter 10(3):16 2003 Detail-Document#: 190320 (subscription needed) http://www.prescribersletter.com
  5. Omari TI et al, Effect of baclofen on esophagogastric motility and gastroesophageal reflux in children with gastroesophageal reflux disease. A randomized controlled trial. J Pediatr 2006, 149:468 PMID: 17011315 - Di Lorenzo C Gastroesophageal reflux. Not a time to relax. J Pediatr 2006, 149:436 PMID: 17011308
  6. Prescriber's Letter 15(12): 2008 Common Oral Medications that May Need Tapering Detail-Document#: 241208 (subscription needed) http://www.prescribersletter.com
  7. Deprecated Reference
  8. Muanda FT, Weir MA, Bathini L et al. Association of baclofen with encephalopathy in patients with chronic kidney disease. JAMA 2019 Nov 9; PMID: 31705755 - Chauvin KJ, Blake PG, Garg AX et al. Baclofen has a risk of encephalopathy in older adults receiving dialysis. Kidney Int. 2020;98(4):979-988 PMID: 32450156 https://www.kidney-international.org/article/S0085-2538(20)30552-4/fulltext - Wolf E, Kothari NR, Roberts JK et al. Baclofen toxicity in kidney disease. Am J Kidney Dis. 2018;71(2):275-280 PMID: 28899601 https://www.ajkd.org/article/S0272-6386(17)30846-6/fulltext
  9. Su Zhang VR, Niu F, Lee EA et al Safety of baclofen versus tizanidine for older adults with musculoskeletal pain. J Am Geriatr Soc. 2023 Mar 29 PMID: 36989193
  10. Hwang YJ, Chang, SR, Brotman DJ et al Baclofen and the Risk of Encephalopathy: A Real-World, Active-Comparator Cohort Study. Mayo Clinic Proceedings. 2023. April 5. PMID: 37028980 https://www.mayoclinicproceedings.org/article/S0025-6196(22)00649-8/fulltext
  11. Hwang YJ, Chang AR, Brotman DJ, Inker LA, Grams ME, Shin JI. Baclofen and the risk of fall and fracture in older adults: A real-world cohort study. J Am Geriatr Soc. 2023 Nov 7. PMID: 37933734 https://agsjournals.onlinelibrary.wiley.com/doi/abs/10.1111/jgs.18665

Component-of

amantadine/baclofen/diclofenac/gabapentin/lidocaine