About mexiletine
Class IB antiarrhythmic sodium-channel blocker
Used for
- Certain serious ventricular heart rhythm problems, such as sustained ventricular tachycardia.
Usual adult dose
Often started at 150 mg every 8 hours; adjusted by a specialist, usually within 200–300 mg every 8 hours.
Common side effects
- Nausea, heartburn, or stomach discomfort
- Dizziness, tremor, or coordination problems
- Blurred vision
- Irregular heartbeat or low blood pressure
Important warnings
- Used for serious heart rhythm disorders under specialist supervision.
- Can worsen arrhythmias or cause new rhythm problems.
- Use caution with liver disease, heart failure, or conduction disorders.
- Seek urgent care for fainting, severe chest pain, or a new irregular heartbeat.
Pregnancy
Human pregnancy data are limited; use only when the expected benefit outweighs potential risk.
Breastfeeding
It is not known whether mexiletine passes into breast milk; discuss risks with a clinician.
Interactions
- Theophylline levels may rise, increasing toxicity risk.
- Caffeine levels may rise, especially with liver enzyme inhibitors.
- Phenytoin, rifampin, and phenobarbital may lower mexiletine levels.
- Use with other rhythm medicines requires monitoring.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.