Verapamil
Why has my veterinarian prescribed this medicine?
Verapamil is used to treat high blood pressure and enlarged heart (hypertrophic cardiomyopathy), and to decrease the heart rate. Verapamil decreases the heart’s need for blood and oxygen and therefore reduces the amount of work the heart must do. It also helps the heart beat more regularly.
Verapamil is not available as a veterinary preparation. This is also the case in Australia, however Australian veterinarians can prescribe this agents to dogs and cats with no further paper work required. Therefore I suggest you delete the following sentence: Your veterinary surgeon may ask you to sign a consent form so a preparation licensed for humans can be used to treat your pet.
How does this medicine work?
Verapamil is a calcium channel-blocking agent, which acts by selectively inhibiting the influx of calcium ions into vascular smooth muscle cells and heart muscle cells.
How do I give this medication?
- Give this medication to your pet as directed by your veterinarian. READ THE LABEL CAREFULLY.
- If the medicine is a liquid, measure the dose with reasonable care.
- Try to give this medication at about the same time(s) each day.
- DO NOT give the pet more medicine than directed and DO NOT give the medicine more often than directed.
- Try not to miss giving any doses.
- DO NOT discontinue the medication without first checking with your veterinarian. Contact your veterinarian in advance if your pet needs a repeat prescription.
What do I do if I miss giving a dose?
Give the dose as soon as possible. If it is almost time for the next dose, skip the missed dose, and continue with the regular schedule. Do not give the pet two doses at once.
How do I store this medicine?
Keep this medicine out of reach of children. Store this medicine in a cool, dry place at room temperature. Store away from heat and direct sunlight. Do not store this medicine in the bathroom, near the kitchen sink or in damp places. The medicine may break down if exposed to heat or moisture.
Potential side effects
- Other side effects include depression, stomach upset and low blood pressure.
- Other side effects may occur. If you notice anything unusual, contact your veterinarian.
Possible drug interactions
- Make sure to tell your veterinarianwhat other medication you are giving to your pet.
- Quite often your veterinarian may prescribe two different medications, and a drug interaction may be anticipated. In this case, your veterinarian may vary the dose and/or monitor your pet more closely.
- Although drug interactions may occur, it does not mean that there is necessarily a high risk of any of these occurring.
- Contact your veterinarian if your pet experiences any unusual reactions when different medications are given together.
© Copyright 2025 LifeLearn Inc. Used and/or modified with permission under license. This content written by LifeLearn Animal Health (LifeLearn Inc.) is licensed to this practice for the personal use of our clients. Any copying, printing or further distribution is prohibited without the express written consent of LifeLearn. This content does not contain all available information for any referenced medications and has not been reviewed by the FDA Center for Veterinary Medicine, or Health Canada Veterinary Drugs Directorate. This content may help answer commonly asked questions, but is not a substitute for medical advice, or a proper consultation and/or clinical examination of your pet by a veterinarian. Please contact your veterinarian if you have any questions or concerns about your pet’s health. Created on Aug 2, 2015.