• See Also
  1. Class Ib Antiarrhythmic Drug
  • Indications
  1. Ventricular Arrhythmia
    1. Other Antiarrhythmics are preferred
  • Contraindications
  1. Structural heart disease (prior Myocardial Infarction, Systolic Dysfunction)
  • Mechanism
  1. Class Ib Antiarrhythmic Drug
  2. Decreases automaticity at AV Node and ectopic focil
  3. Increases refractory period in His Bundle, Purkinje Fibers, ventricle and accessory pathways
  • Precautions
  1. Other Antiarrhythmics are preferred (consult cardiology)
  2. Consider dose adjustment in severe liver disease
  3. Proarrhythmic
    1. Higher mortality in non-life threatening ventricular Arrhythmia and structural heart disease
  • Dosing
  1. Start: 200 mg every 8 hours with food
  2. Titrate dose to effect
    1. May convert to twice daily dosing when effective dose identified
  3. Maximum
    1. Three times daily: 1200 mg/day (400 mg/dose)
    2. Twice daily: 900 mg/day (450 mg/dose)
  4. Renal Dosing for eGFR <10 ml/min
    1. Decrease to 50 to 75% of typical dose
  • Safety
  1. Avoid in Lactation
  2. Pregnancy Category C
  • Adverse Effects
  1. Proarrhythmic
  2. Hepatotoxicity
  3. Neurotoxicity
  4. Seizures
  • Drug Interactions
  1. Mexiletine may increase levels of other medications
    1. Theophylline
  2. Other medications may effect drug levels of Mexiletine
    1. Cimetidine
    2. Fluvoxamine
    3. Phenobarbital
    4. Phenytoin
  • Resources
  1. Mexiletine (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ab73778b-6794-441c-b127-610a6d0733ea
  • References
  1. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 74-5
  2. van der Ree (2022) Europace 24(11):1809-23 +PMID: 36036670 [PubMed]