Rx Information
Order Process Information
Login Required
    Free Standard Shipping on orders over $59
0 items in the shopping cart
Pet Rescue Rx. - Profits go to a shelter of your choice!
0 items in the shopping cart
100% of our Profits are Donated to an Animal Shelter or Rescue Group of your choice!


Mexiletine by Teva Pharmaceuticals

Pharmacy Required
New Prescription
Choose One:

Shipping Information   Order Process Information

Mexiletine is an antiarrhythmic agent. It is used to treat ventricular arrhythmias (irregular heart beats associated with the ventricles of the heart). It is often used in conjunction with other heart medications.

Side Effects

  • The most common side effects are related to the GI tract including nausea and vomiting. Giving food with mexiletine has been shown to decrease the incidence of GI side effects.
  • Other possible side effects include central nervous system signs such as dizziness, loss of balance and trembling, shortness of breath, and cardiac signs including PVCs or chest pain.
  • Rare side effects reported in humans include seizures, and bone marrow suppression.


  • Mexiletine should be used with extreme caution in animals with the following conditions: 2nd or 3rd degree AV heart block, intraventricular conduction abnormality, sinus node function abnormality, cardiogenic shock, congestive heart failure, myocardial infarction, liver dysfunction, hypotension, or seizure disorders.

Drug Interactions

  • Concurrent use with lidocaine increases the likelihood of adverse effects.
  • There are a number of drugs that may cause drug interactions either through changing the rate of absorption or changing the rate of metabolism of mexiletine. This list includes: antacids, atropine, opiates, cimetidine, griseofulvin, metoclopramide, phenobarbital, phenytoin, primidone, rifampin, theophylline.
  • Drugs which change urinary acidity may affect the renal excretion of mexiletine. These drugs include methionine, ammonium chloride, potassium phosphate, sodium phosphate, citrates, sodium bicarbonate, and carbonic anhydrase inhibitors.


Overdose with mexiletine carries a significant risk of toxicity. It is reported in the human literature that central nervous system signs precede cardiovascular signs. In experimental work in dogs, a four fold overdose consistently produced CNS signs within 10 minutes of oral administration. If recognized in time, GI emptying protocol should be attempted in conjunction with urinary acidification and supportive care.


Common Drug Name

Common Brand Names
No generic products are available. 
Refrigerate oral suspension. Store other forms at room temperature in a tight, light resistant, childproof container.

Mexiletine is an antiarrhythmic agent. It is used to treat ventricular arrhythmias (irregular heart beats associated with the ventricles of the heart). It is often used in conjunction with other heart medications. 

Dose and Administration 
Always follow the dosage instructions provided by your veterinarian. If you have difficulty giving the medication, contact your veterinarian. Giving mexiletine with a meal may decrease some side effects. If you miss a dose, give it as soon as you remember. If it is almost time for the next dose, skip the one you missed and go back to the regular schedule. Do not give 2 doses at once. This medication should only be given to the pet for whom it was prescribed. 

Possible Side Effects 
The most common side effects are vomiting and loss of appetite. Consult your veterinarian if you notice any of the above side effects. If your pet experiences an allergic reaction to the medication, signs may include facial swelling, hives, scratching, sudden onset of diarrhea, vomiting, shock, seizures, pale gums, cold limbs, or coma. If you observe any of these signs, contact your veterinarian immediately. 
Not for use in animals hypersensitive (allergic) to mexiletine. If given to nursing mothers, mexiletine will enter the milk, so the use of a milk replacer is recommended. Do not use in animals with 2nd or 3rd degree AV block (a type of heart condition). Use with caution in animals with severe congestive heart failure, acute myocardial infarction, liver disease, hypotension (low blood pressure), or seizure disorders. Consult with your veterinarian regarding physical examinations or laboratory testing necessary prior to and during treatment with mexiletine. 

Drug and Food Interactions
Consult your veterinarian before using mexiletine with any other medications, including vitamins and supplements, phenobarbital, primidone, griseofulvin, rifampin, tolbutamide, opiates, antacids containing aluminum/magnesium, or urinary acidifiers (e.g., methionine, ammonium chloride, or certain diets formulated to prevent or remove bladder stones), cimetidine, or theophylline, since interactions may occur. Metoclopramide or drugs or diets that alkalinize the urine may increase the effects of mexiletine. 

Signs of Toxicity/Overdose 
May see tremors, unsteadiness, staggering, depression, seizures, weakness, or shortness of breath. If you know or suspect your pet has had an overdose, or if you observe any of these signs in your pet, contact your veterinarian immediately. 
Keep this and all other medications out of the reach of children and pets

Customer Reviews

Be the first to write a review of this product.

Pet Rescue Rx Free Shipping