Medication: Digoxin

Your cat has been prescribed digoxin for the treatment of certain types of abnormal heart rhythm or congestive heart failure. 

Key points: 
• Cardiac glycoside. 
• Do not use in animals with ventricular arrhythmias/tachycardia.   
• Do not use in animals with atrioventricular block (heart block). 
• Not recommended for use in animals with outflow tract obstructions (eg pulmonic stenosis, aortic stenosis, hypertrophic obstructive cardiomyopathy). 
• Cats are more susceptible to the toxic effects of digoxin than dogs and therefore digoxin is usually avoided in this species.  
• Use with extreme caution in animals with kidney disease, low protein levels and ascites (fluid build up in the abdomen/tummy) .
• Use with caution in pets with abnormal electrolyte levels, particularly potassium.  
• Use with caution in pregnant or lactating animals. 
• Dosage: twice daily (every 12 hours). 

This information sheet is designed to help answer commonly asked questions and help you give the medication safely and effectively to your pet. It does not contain all available information for this medication. If you have other questions or need more information, contact your veterinarian or pharmacist. Always follow the dosing instructions provided by your veterinarian. 

Name 

• Digoxin (di – JOX – in). 

Brand name 

• Lanoxin® (Europe & UK, US). 
• Lanoxicaps® (US).  
• Toloxin® (US).  
• Cardoxin® (US).  
• Digitek® (US). 

Class of medication 

• Cardiac glycoside. 
• Anti-arrhythmic. 
• Positive inotrope. 

Storage 

• Store at room temperature (>15°C (59°F); <30°C (86°F)) and in a dry environment away from direct light. 

Your veterinarian has prescribed digoxin for the treatment of: 

• Arrhythmias: 
  • Atrial fibrillation. 
  • Supraventricular tachycardia (SVT).
• Congestive heart failure. 

Digoxin is given orally, as a tablet or liquid, twice daily. Both tablets and liquid are usually administered directly into your pet’s mouth but may be given along with some food. If you are giving drops to your pet make sure you measure the dose very carefully as it is easy to give an overdose. Cats frequently dislike the taste of the liquid form and it should be given with high-flavored foods or treats. 

Digoxin may be given alongside other medications such as other anti-arrhythmic drugs (eg diltiazem), diuretics, positive inotropes (eg pimobendan), or ACE inhibitors. 

The following side-effects have been reported: 

• Digestive tract disorders (anorexia, weight loss, vomiting or diarrhea). 
• Tiredness or behavior changes. 
• Cardiac arrhythmia. 
• Cats are more sensitive to the toxic effects of digoxin than dogs.  

Serious side-effects include: 

• Collapse. 
• Severe tiredness. 
• Muscle weakness. 

Drug interactions 

• Some drugs reduce digoxin absorption: antacids, cimetidine, metoclopramide, oral neomycin, some chemotherapy agents, and penicillamine. 
• Some drugs reduce removal of digoxin from body causing an increase in blood levels: benzodiazepines, quinidine, anticholinergics, succinylcholine, verapamil, certain antibiotics such as tetracycline, clarithromycin, and erythromycin. 
• Drugs that cause a lowering of potassium in the blood may increase risk of digoxin toxicity: loop or thiazide diuretics, amphotericin B, corticosteroids, ACTH, some laxatives, glucagon, dextrose or dextrose-insulin infusion, sodium polystyrene sulfonate. 
• Thyroid replacement therapy and spironolactone may also change digoxin levels. 
• Spironolactone may enhance or decrease the toxic effects of digoxin. 

Digoxin tablets should be administered according to your veterinarian’s instructions. The treatment course is usually long-term, potentially lifelong. If toxicity is suspected the treatment should be stopped. If treatment is stopped, any effects will cease within a few days, though effects may last longer in animals with liver or kidney disease.  

Dispose of any unused digoxin safely – do not flush down the toilet or sink. Ask your veterinary team if they take back medication for disposal. Do not save digoxin for future use or give to other pets. 

If you miss a dose, give the dose as soon as possible but do not give a double dose. Make sure the dose given does not exceed the total recommended dose in any 24-hour period. 

If your pet is unwell, contact your veterinarian for advice. 

Digoxin should only be given to the cat that it has been prescribed for: 

• Do not give to other pets in the household. 
• Do not give to animals with digitalis intoxication. 
• Do not use in animals with ventricular fibrillation. 
• If accidentally given to other pets, contact your veterinarian for advice. 

If accidentally consumed by a person, speak to your primary care physician or poison control center.  

Levels of digoxin in the blood will be monitored by your veterinarian if there are signs of overdose or poor effect, especially when starting therapy. Appetite, body weight, electrolytes, kidney function, and ECG will be monitored during treatment. 

Further information 

If you have any concerns, further information on digoxin can be found on the package insert. 

Europe & UK

• There are no licensed products for dogs and cats in UK and Europe. 

USA

• There are no licensed products for dogs or cats in US. 

Always follow the recommended dosage and contact your veterinary team or pharmacist if you have any questions regarding your cat’s medication.