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Blood pressure issues are a common condition for humans—but did you know they’re also common in dogs and cats? Blood pressure is an important part of cat and dog health and wellness, and our pets can experience both high and low blood pressure, as well as other heart diseases. For high blood pressure, your veterinarian may prescribe a drug like amlodipine. 

What is amlodipine? 

Amlodipine is a vasoactive drug—that means it’s a medication for the heart and blood pressure. In dogs and cats, it’s typically used to treat secondary hypertension, which is high blood pressure caused by another condition. Secondary hypertension can be caused by hyperthyroidism, diabetes, kidney disease and cardiomyopathy.  

Amlodipine can also be used to treat proteinuria—or high protein levels in the urine—in cats; for dogs, it is also used to treat congestive heart failure. It’s often used in conjunction with ACE inhibitor drugs. Amlodipine brand names include Amodip, Katerzia and Norvasc.  

How do I give my pet amlodipine? 

A prescription from your veterinarian can be filled at a pet pharmacy and will typically be given orally in tablet form. If you have a pup who is wise to you hiding pills in treats, amlodipine can be given as a compounded liquid solution—but it needs to be carefully measured. Give your pet amlodipine medication with food, and always give it only as directed by your veterinarian. Don’t stop giving this medication without consulting your vet, as you may need to taper the dose.  

Missing a dose of amlodipine can cause your pet’s blood pressure to spike, which can lead to complications. If you miss a dose, give it as soon as you remember—unless it is close to the next time administration is due. Don’t give two doses at the same time. If you have any questions about your pet’s missed dose or regular dosing schedule, consult your veterinarian.

How does amlodipine work? 

Amlodipine dilates the blood vessels, improves blood flow and should ultimately lower your pet’s blood pressure. It does this by inhibiting the body’s calcium channels, reducing the amount of calcium in blood vessels and arteries. That helps relax the blood vessels, increasing blood flow and making it easier for the heart to pump. Increasing blood flow and lowering the effort the heart must make to pump blood is what helps lower blood pressure. 

How long does it take for amlodipine to work?

In dogs and cats, amlodipine typically starts working within 1–2 hours but can have a slow onset. This can be a positive aspect because it may not cause as many side effects. You might not notice any visible results at first, so your veterinarian may order lab tests to ensure it’s working properly.  

Amlodipine is also short-acting and should leave your dog’s system in 24–30 hours without re-dosing—except in the case of kidney disease, in which case your pet will process it more slowly. It is not known exactly how long it stays in a cat’s system. 

What’s the right dosage of amlodipine for dogs? 

Amlodipine is usually titrated for dogs —meaning you will start with a low dose and gradually give your pet more each day until it is bringing the right control for your pet’s symptoms. The dosage for your pup may also be lower or higher than the average depending on your pet’s condition and any other medications they take. With all factors considered, the typical amlodipine dosage for dogs is usually 0.2–0.4 milligrams per kilogram of weight per day.  

What’s the right amlodipine cat dosage? 

Amlodipine is also titrated for cats, gradually increasing over time. The dosage is normally 0.625–1.25 milligrams, depending on the cat’s weight, condition and other factors. You’ll typically be instructed to start at the lower end and increase the dose with supervision from your veterinarian. If provided too much, this medication can negatively affect normal blood pressure in cats.  

What are the side effects of amlodipine? 

Amlodipine side effects in cats and dogs are similar and can include appetite loss, weakness, lethargy, vomiting and weight loss. Because this medication affects arteries and blood flow, more serious side effects like increased heart rate, swelling of the limbs and collapse have also been noted. Amlodipine can affect the body’s ability to clot blood, so increased bleeding may occur. Dogs may experience gingival hyperplasia, which is an overgrowth of the gum tissue. 

Your pet can also be allergic to amlodipine. If they’re allergic, this medication’s side effects can include diarrhea or vomiting, itching and hives, facial swelling and pale gums. These are symptoms of allergic reaction and require immediate veterinary care. However, allergic reactions and side effects of amlodipine are typically rare if administered properly.  

High blood pressure is a serious condition in both cats and dogs, and it can cause seizures, heart murmurs and even blindness if left untreated. Thankfully, with medications like ACE inhibitors and amlodipine, your pet has a greater chance of living a fuller life. 

Can my pet overdose on amlodipine? 

Yes—both cats and dogs can overdose on amlodipine, which is why administration of this medication is titrated to therapeutic levels and is typically accompanied by laboratory tests. While the exact amlodipine dosage that causes overdose may depend on various factors, if your pet has ingested more than their prescribed amount, contact your veterinarian.  

Amlodipine overdoses can cause hypotension—or low blood pressure—as well as weakness, disorientation, vomiting, slowed heart rate and collapse. If you notice these signs, get your pet to your veterinarian as soon as possible so they can induce vomiting and provide treatment.  

What are the risk factors for amlodipine? 

Amlodipine is a powerful blood pressure medication and should be used cautiously with other drugs that lower blood pressure, like vasodilators, diuretics and beta-blockers. It should also be used cautiously in pets with heart failure or those who are pregnant or lactating, and it shouldn’t be given to pets with liver disease, liver failure or aortic stenosis.  

Always tell your veterinarian about any cat or dog vitamins and supplements or other medications your pet may be taking. To help prevent adverse reactions, the vet will likely want to see your pet for regular checkups to monitor blood pressure and potassium levels.