Pimobendan and Enalapril for Dogs: Uses, Dosage, and Side Effects

Pimobendan and enalapril are commonly prescribed together to help manage congestive heart failure (CHF) in dogs caused by degenerative mitral valve disease or dilated cardiomyopathy. 

Some dogs receive these medications as a compounded combination after they have been stabilized on each drug individually.

Here’s how enalapril/pimobendan works, when veterinarians prescribe it, possible side effects, dosing guidance, and important safety information.

What Is Enalapril/Pimobendan for Dogs?

Enalapril/pimobendan is a compounded veterinary medication used to help manage congestive heart failure (CHF) in dogs caused by degenerative mitral valve disease (MVD) or dilated cardiomyopathy (DCM).

Although enalapril and pimobendan (the active ingredient in Vetmedin®) may be prescribed separately, they are commonly used together to manage heart disease.

Enalapril is FDA-approved for human use under the brand names Epaned®, Vasotec®, and generic enalapril. Although it is not FDA-approved as a veterinary medication, veterinarians may legally prescribe it extra-label when appropriate.

Pimobendan is not FDA-approved for human use.

Compounded enalapril/pimobendan: Instead of prescribing enalapril and Vetmedin® separately, your veterinarian may recommend a compounded combination containing enalapril and pimobendan. 

This formulation is intended only for dogs that are already stabilized on both medications. It is not used when a dog is first starting treatment or when medication doses still need adjustment.

Compounded medications may be prescribed when:

• Your dog has difficulty taking the commercially available formulation.
• The required dosage strength is not commercially available.
• Your dog is allergic to an ingredient in the FDA-approved medication.

Compounded medications are not FDA-approved. They are prepared by a veterinarian or licensed pharmacist to meet an individual patient's specific needs.

Safety Considerations for Enalapril/Pimobendan

Dogs receiving enalapril/pimobendan require close veterinary monitoring, especially those with severe congestive heart failure (CHF).

Your veterinarian may recommend:

• Blood and urine tests to monitor kidney and liver function
• Blood pressure monitoring
• Chest X-rays
• An electrocardiogram (ECG)

Do not use enalapril/pimobendan in dogs that have had an allergic reaction to either medication.

Tell your veterinarian about all of your dog's medications, vitamins, supplements, and medical conditions before starting treatment, as drug interactions may increase the risk of side effects.

Enalapril should be used with caution in dogs with:

• Kidney disease
• Low blood sodium (hyponatremia)
• Cerebrovascular insufficiency
• Preexisting blood cell abnormalities
• Systemic lupus erythematosus (SLE)
• Pregnancy

Pimobendan should be used with caution in dogs with:

• Uncontrolled cardiac arrhythmias (irregular heartbeats)

At the time of publication, safety studies had not been performed in:

• Dogs younger than 6 months of age
• Dogs with congenital heart defects
• Dogs with diabetes mellitus
• Dogs with other serious internal diseases

How Enalapril and Pimobendan Work

Enalapril and pimobendan work together to help the heart pump more efficiently and improve blood flow in dogs with congestive heart failure.

Enalapril: Enalapril is an angiotensin-converting enzyme (ACE) inhibitor. ACE inhibitors lower blood pressure by blocking an enzyme that causes blood vessels to constrict.

As the blood vessels relax and widen, blood flows more easily throughout the body, reducing the workload on the heart.

Pimobendan: Pimobendan helps the heart in two important ways.

• It causes vasodilation, relaxing blood vessels so blood can circulate more easily.
• It improves the heart muscle's ability to contract, allowing the heart to pump more blood to the rest of the body.

By widening the veins, pimobendan helps reduce the buildup of fluid in the lungs and body. Widening the arteries also reduces the resistance the heart must pump against, improving blood flow to the body's organs.

How To Give Enalapril/Pimobendan

Give enalapril/pimobendan exactly as directed by your veterinarian.

Administration tips:

• Follow the directions on the prescription label or those provided by your veterinarian.
• Ask your veterinarian whether this medication should be given with or without food.
• Always make sure your dog has access to plenty of fresh water while taking this medication.
• Do not stop or reduce the dose unless instructed by your veterinarian. If treatment needs to be discontinued, your veterinarian will typically recommend gradually tapering the medication under their supervision.

Missed a Dose?

If you miss a dose of enalapril/pimobendan, contact your veterinarian for guidance. In many cases, they may recommend giving the missed dose when you remember. 

However, if it is almost time for your dog's next scheduled dose, they may advise skipping the missed dose and resuming the normal dosing schedule.

Do not give extra or double doses.

Enalapril/Pimobendan Side Effects

Enalapril/pimobendan is generally well tolerated by many dogs, but side effects can occur.

Possible side effects include:

• Gastrointestinal upset (decreased appetite, vomiting, or diarrhea)
• Weakness
• Lack of coordination
• Low energy (lethargy)
• Low blood pressure (hypotension)
• Difficulty breathing
• Increased thirst and urination

Human Side Effects

Enalapril is also prescribed for people, but human and veterinary doses differ. Pimobendan is not approved for use in humans.

Humans should never take medication prescribed for pets, and pets should never receive medication prescribed for people.

Enalapril can cause serious harm to a developing fetus. If you are pregnant, trying to become pregnant, or breastfeeding, avoid ingesting this medication or speak with your veterinarian about alternative treatment options for your pet.

If you accidentally ingest this medication, contact your physician immediately or call the National Poison Control Center at 800-222-1222.

When To Call Your Veterinarian

Contact your veterinarian if:

• Your dog develops severe side effects.
• Your dog's condition worsens or does not improve with treatment.
• You suspect your dog has received an overdose.
• You have additional questions or concerns about using enalapril/pimobendan.

Enalapril/Pimobendan Overdose

An overdose of enalapril/pimobendan is a medical emergency and requires immediate veterinary attention.

Signs of an overdose may include:

• Vomiting
• Fast heart rate (tachycardia)
• Abnormally high blood pressure (hypertension)
• Abnormally low blood pressure (hypotension), which may cause:
  • Low energy (lethargy)
  • Weakness
  • Fainting (syncope)
  • Collapse

If you suspect your dog has received an overdose, contact your veterinarian immediately, seek emergency veterinary care, or contact an animal poison control center. Consultation fees may apply.

• Pet Poison Helpline: (855) 764-7661
• ASPCA Animal Poison Control: (888) 426-4435

How To Store Enalapril/Pimobendan

Store enalapril/pimobendan according to the prescription label to help maintain its safety and effectiveness.

Storage instructions:

• Store at controlled temperatures between 68 F and 77 F (20 C–25 C).
• Keep the container tightly closed to protect the medication from moisture and light.
• Keep out of reach of children and pets.