Pimobendan

Major Uses

Pimobendan is a phosphodiesterase III inhibitor that has calcium sensitizing properties and blocks the inactivation of cyclic AMP, which improves cardiac output and quality of life. It is most often used in the treatment of congestive heart failure in dogs.

Pimobendan decreases heart rate and increases heart contractility to help the heart pump more effectively. Its use has contributed to improved survival in some dogs, such as Doberman Pinschers. The drug is approved in Canada and Europe to treat heart failure associated with valvular insufficiency or dilated cardiomyopathy. It is approved by the Food and Drug Administration for use in animals.

Common Precautions

Side effects of treatment with pimobendan include diarrhea, vomiting, and loss of appetite. Incoordination, seizures, uneasiness, polyuria, polydypsia, and other side effects are also possible. Pimobendan is not for use in animals with aortic stenosis or hypertrophic cardiomyopathies. Higher doses of the drug are linked to exaggerated myocardial contractility and jet lesions to the myocardium.

It is not known if this drug is safe for use in pregnant, lactating, or breeding animals. Dogs suffering from congestive heart failure should be monitored for arrhythmias during therapy with pimobendan. Pimobendan is known to interact with certain other medications and supplements, including other positive inotropes, beta-blockers, calcium-channel blocks, and others.

Pimobendan should not be used in animals with a known allergy or hypersensitivity to the drug. Any known or suspected overdose should be reported to a veterinarian right away.

Storage

Pimobendan should be stored at room temperature, in a tight fitting and light-resistant container, and out of the reach of animals and children.

Administration

Pimobendan is available as 1.25 mg and 5.0 mg capsules.

In dogs, the typical dose is 0.05 to 0.15 mg/lb (0.1 to 0.3 mg/kg) every 12 hours. Doses should be given one hour before meals. Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.

If a dose of pimobendan is missed, it should be given as soon as possible. If it is almost time for the next dose, the missed dose should be skipped and the regular schedule resumed. Two doses of this medication should not be given at the same time.