Petmedin (Pimobendan 5mg) Tablets

Petmedin general information

What is Petmedin used for?

If your dog is having difficulty breathing and is persistently coughing, these may be symptoms of congestive heart failure (CHF).  This heart condition can have a severe impact on your dog’s quality of life and can also become life-threatening.  Petmedin tablets 5mg are used to reduce symptoms of CHF, which improves your dog’s quality of life and helps your dog to feel better and live longer.

Congestive heart failure in dogs

A common cause for CHF in dogs is mitral valve disease, also known as mitral valve insufficiency.  The mitral valve is located between the left atrium and the left ventricle, which are the right-hand chambers of the heart.  If the mitral valve degenerates and thickens, it cannot function properly and can become leaky, which allows blood to flow back into the atrium from the ventricle.  Mitral valve disease usually affects smaller dog breeds, such as Spaniel and Dachshund.

Dilated cardiomyopathy is another common cause of CHF in dogs.  This is when the heart muscle becomes weakened so that it does not pump efficiently, which can lead to an enlarged heart and the leaking of one or more valves.  This condition in dogs is not caused by heart disease or blocked arteries, as it is in humans.  It is often an inherited condition, and some breeds have a predisposition such as Doberman, Great Dane, Boxer and Spaniel.  CHF can also be the result of an infection or a toxin.

CHF puts increased strain on the heart as it works harder to pump blood.  As the heart struggles to pump blood around the body, fluid can build-up in the tissues, particularly in the heart itself, the lungs and the abdomen.

Symptoms of CHF in dogs

Symptoms of CHF in dogs include a persistent cough, reduced exercise tolerance, difficulty breathing, increased breathing rate, panting, loss of appetite and fatigue.  Also, any signs of feeling unwell, like lethargy or weakness.  A heart murmur is also an early sign of CHF.  

Petmedin tablets 5mg are used to treat susceptible breeds and can also be used if your dog has been diagnosed with an enlarged heart but does not show symptoms of CHF.  Early treatment with Petmedin before symptoms of CHF become life-threatening can help delay the onset of CHF and also increase your dog’s life expectancy.  Petmedin tablets 5mg can be used in conjunction with other heart medications such as diuretics (water tablets).

How does Petmedin work?

Petmedin tablets 5mg contain pimobendan, a veterinary medicine that is used to treat congestive heart failure (CHF) in dogs. 

Pimobendan in Petmedin tablets 5mg is classed as an inodilator.  An inodilator is a drug that works by a combination of two mechanisms of action to help the heart pump more efficiently.  These mechanisms are increasing the strength of contraction of the heart muscle and widening the arteries that take blood from the heart.

Pimobendan in Petmedin tablets has a positive inotropic action, which means that it increases the strength of the muscular contraction of the heart muscle cells (myocytes).  Calcium is essential for the contraction of myocytes and binds to the contractile protein troponin inside the myocytes.  Pimobendan increases the sensitivity of the myocytes to calcium and promotes calcium binding to enable contraction. 

Pimobendan in Petmedin tablets 5mg is also a vasodilator and acts directly on the blood vessels that take blood away from the heart, by inhibiting an enzyme called phosphodiesterase 3 (PDE3).  This enzyme mediates blood vessel contraction, which narrows the blood vessels.  By inhibiting PDE3, Pimobendan causes vasodilation (widening), relaxing peripheral blood vessels, which reduces the pressure and workload on the heart and helps it to pump more efficiently.

What does Petmedin contain?

Petmedin contains the active ingredient pimobendan, a calcium sensitizer and vasodilator that is used to treat congestive heart failure (CHF) in dogs. 

What are the side effects of Petmedin?

Most medications have some side effects.  Some side effects are commonly experienced when taking Petmedin, but others are not so common, and you should discuss any problems or concerns with your veterinarian. 

Common side effects you may see in your dog when taking Petmedin include vomiting, poor appetite, lethargy, diarrhoea, shortness of breath (dyspnea), weakness, impaired balance and coordination (ataxia), fainting.

When should Petmedin not be used?

Have a talk with your veterinarian before giving Petmedin to your dog so that you have a full understanding of what this medicine is for and how to use it.  There are some reasons for not using a medication; these are called contraindications, and you should consider the following before giving Petmedin to your dog:

• Is your dog allergic to pimobendan or any ingredients in Petmedin?
• Is your dog pregnant or lactating?
• Is your dog younger than 6 months old?
• If your dog does not have clinical evidence of heart failure, Petmedin may not be a suitable medication
• Does your dog have a congenital heart disease?
• Does your dog have diabetes or another serious metabolic disease?

What medications interact with Petmedin?

No drug interactions have been described for Petmedin.

How should Petmedin be taken and for how long?

You should give Petmedin tablets 5mg orally to your dog twice a day, morning and evening, with approximately 12 hours between doses.  The dose you give your dog should be as recommended by your vet and is usually 0.5mg/kg (0.23mg/lb) body weight per day.  You should see an improvement in your dog’s health within a week, but you should continue to give Petmedin tablets 5mg to your dog as long as is recommended by your veterinarian, which may be for the rest of your dog’s life.  Your vet may also recommend other drugs for treating heart failure as well as Petmedin tablets 5mg, as there are no interactions between these drugs. 

Missed dose of Petmedin

If you miss a dose of Petmedin tablets 5mg give it as soon as you remember, unless it is time to give the next dose, then skip the missed dose.  Do not give a double dose.

How should Petmedin be stored?

You should store your Petmedin tablets 5mg below 25°C in a cool dry place.