Pimobendan

Pimobendan In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• An inodilator exhibits both positive inotropic and vasodilatory effects.
• The positive inotropic effects occur through the sensitization of the myocardial contractile apparatus to intracellular calcium and the inhibition of phosphodiesterase (PDE) III.
• This calcium sensitization enables a boost in cardiac contractility without a concurrent rise in myocardial oxygen demand.
• Vasodilation is achieved through the inhibition of PDE III and V, leading to dilation of both arteries and veins.
• Additionally, the inodilator functions as a positive lusitrope and mildly inhibits platelet aggregation in dogs at standard doses.

Uses of Pimobendan

• Management of congestive heart failure arising from valvular insufficiency (mitral and/or tricuspid regurgitation) or dilated cardiomyopathy (DCM) in dogs.
• This medication is recommended in conjunction with other congestive heart failure therapies like furosemide and ACE inhibitors.
• It has demonstrated effectiveness in delaying the onset of heart failure or sudden death in Dobermans with preclinical DCM and in dogs aged 6 years or older, weighing 4–15 kg, with myxomatous mitral valve disease (MMVD).
• Vetmedin is authorized for use in preclinical DCM in Dobermans and MMVD.
• Additionally, there is evidence supporting its efficacy in treating pulmonary hypertension secondary to mitral valve disease in dogs.
• While it has been used in cats with heart failure associated with systolic dysfunction, its use in cats is not officially authorized, as pharmacokinetics may differ between cats and dogs.

Dose of Pimobendan in Dogs and Cats

Dogs:

• 0.15 mg/kg i.v. single dose.
• Oral pimobendan can be continued 12 hours after administration of the injection.

Dogs, Cats:

• 0.1–0.3 mg/kg p.o. q12h 1 hour before food.

Side Effects of Pimobendan in Dogs and Cats

• A moderate positive chronotropic effect and vomiting may occur in some cases, which may be avoided by dose reduction.

Contraindications of Pimobendan in Dogs and Cats

• Do not use in hypertrophic cardiomyopathy and in cases where augmentation of cardiac output via increased contractility is not possible (e.g. aortic stenosis).

Some Notes:

• The positive inotropic effects are attenuated by drugs such as beta-blockers and calcium channel blockers (especially verapamil).
• No interaction with digitalis glycosides has been noted.