What is amlodipine?
Amlodipine (brand names: Norvasc®, Amodip®, Copalia®, Katerzia®) is a calcium-channel blocker used for treating high blood pressure, most commonly in cats, to prevent damage to the kidneys, eyes, and brain.
It is used off label (extra label) to treat high blood pressure in cats and dogs. Many drugs are commonly prescribed for off label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada.
In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.
How is amlodipine given?
- Amlodipine is given by mouth, in the form of a tablet or compounded liquid solution.
- It may be given with or without food.
- If vomiting occurs when dosed on an empty stomach, give future doses with food.
- Measure liquid forms carefully.
- Do not miss or skip doses; do not stop this medication before talking to your veterinarian.
This medication should take effect within 1 to 2 hours; however, effects may not be visible, so laboratory tests may be required to evaluate this medication’s effectiveness.
What if I miss giving my pet the medication?
If you miss a dose, give it as soon as you remember, and then wait the recommended time as prescribed by your veterinarian for the next dose. Do not give the pet two doses at once.
Are there any potential side effects?
Side effects in cats may include:
- Vomiting
- Diarrhea
- Lack of appetite
- Sleepiness
Side effects in dogs may include:
- Gingival (gum) overgrowth
Serious adverse reactions may occur. If any of the following signs develop, stop giving amlodipine and contact your veterinarian immediately:
- Very low or very fast heart rate
- Collapse
- Severe weakness
- Changes in urination
- Limb swelling
- Abnormal bleeding
Drug sensitivities can develop over time, with repeated exposure. Your pet may have no reaction after the first few doses but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment. Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.
Are there any risk factors for this medication?
DO NOT USE amlodipine in pets that:
- Are allergic to it
- Are in shock
- Have aortic stenosis
- Have liver failure
USE WITH CAUTION in pets that:
- Have heart failure
- Have liver disease
- Are at risk for low blood pressure
- Are pregnant and/or lactating (safety has not been established)
Are there any drug interactions I should be aware of?
The following medications should be used with caution when given with amlodipine:
- Clopidogrel
- Cyclosporine
- CYP3A4 inducers, such as azole antifungals, negative chronotropes, and hypotensive agents
Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.
Is any monitoring needed with this medication?
- Your veterinarian will monitor your pet’s blood pressure regularly to be sure that the medication is working and to adjust the dose.
- Eye exams and potassium levels may be monitored regularly.
How do I store amlodipine?
- Store at room temperature between 68°F and 77°F (20°C and 25°C) with short trips between 59°F and 86°F (15°C and 30°C) permitted.
- Protect from moisture and light.
- Store the veterinary chewable tablets in the blister packaging until ready to use; tablets removed from the blister pack must be used within 24 hours.
- Store the compounded liquid form between 41°F and 77°F (5°C and 25°C) and protect from light, unless otherwise instructed on the label.
What should I do in case of emergency?
If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet’s weight and symptoms.
