Skip to main content
PetDosageChart

Norvasc (Amlodipine) Dosage for Cats

Calcium channel blocker (antihypertensive) ⏱ Onset: 1-2 hours; full effect in 1-2 weeks ⏳ Duration: 24 hours

This dosage information is for educational purposes only. Always consult your veterinarian before giving any medication to your pet. Dosages may vary based on your pet's health conditions, other medications, and individual factors.

Content reviewed by licensed veterinarians. This information is sourced from veterinary drug references including Plumb's Veterinary Drug Handbook and the Merck Veterinary Manual.

Dosage Calculator

Enter your cat's weight to calculate the recommended dose.

Norvasc Dosage Chart for Cats by Weight

Scroll sideways to see full table

Weight Low Dose Standard Dose Max Dose Frequency
3 lbs (1.4 kg) 0mg 0.5mg 0.5mg once daily
4 lbs (1.8 kg) 0mg 0.5mg 0.5mg once daily
5 lbs (2.3 kg) 0.5mg 0.5mg 0.5mg once daily
6 lbs (2.7 kg) 0.5mg 0.5mg 0.5mg once daily
7 lbs (3.2 kg) 0.5mg 0.5mg 1mg once daily
8 lbs (3.6 kg) 0.5mg 0.5mg 1mg once daily
9 lbs (4.1 kg) 0.5mg 0.5mg 1mg once daily
10 lbs (4.5 kg) 0.5mg 1mg 1mg once daily
12 lbs (5.4 kg) 0.5mg 1mg 1.5mg once daily
14 lbs (6.3 kg) 1mg 1mg 1.5mg once daily
16 lbs (7.3 kg) 1mg 1.5mg 2mg (2.5mg tablet) once daily
18 lbs (8.2 kg) 1mg 1.5mg 2mg (2.5mg tablet) once daily
20 lbs (9.1 kg) 1mg 1.5mg 2.5mg (2.5mg tablet) once daily
25 lbs (11.3 kg) 1.5mg 2mg (2.5mg tablet) 3mg (2.5mg tablet) once daily

What is Norvasc (Amlodipine) used for in cats?

hypertension (high blood pressure) hypertension secondary to chronic kidney disease hypertension secondary to hyperthyroidism retinal protection in hypertensive cats

How to give Norvasc to your cat

Amlodipine is the drug of choice for feline hypertension. The typical starting dose is 0.625 mg (one-quarter of a 2.5 mg tablet) once daily for an average-sized cat. The tiny tablet fragment can be hidden in a pill pocket, soft treat, or wet food. Blood pressure should be rechecked 1-2 weeks after starting and after any dose change. Consistency in daily timing helps maintain stable blood pressure control.

Available Forms

tablet

Give with Food?

Yes — give with food

Side effects of Norvasc in cats

Common side effects

mild decrease in appetite
mild lethargy
gingival hyperplasia (gum overgrowth) with long-term use
mild GI upset

Serious side effects

  • dangerously low blood pressure (hypotension)
  • rapid heart rate (reflex tachycardia)
  • worsening kidney function
  • acute blindness if hypertension is untreated

When to call the vet

Call your vet immediately if your cat shows any of these signs:

  • Sudden blindness, dilated pupils, or bumping into things (hypertensive retinopathy)
  • Extreme lethargy or weakness (possible hypotension from over-dosing)
  • Rapid breathing or open-mouth breathing
  • Seizures or disorientation (hypertensive crisis)
  • Persistent loss of appetite or vomiting

Related Medications for Cats

Anticonvulsant / Analgesic

Neurontin

Gabapentin

For pain management

View dosage chart
Antihistamine

Benadryl

Diphenhydramine

For allergies

View dosage chart
NK1 receptor antagonist / Antiemetic

Cerenia

Maropitant

For vomiting

View dosage chart
H2 receptor antagonist

Pepcid

Famotidine

For stomach acid reduction

View dosage chart

Sources & References

The dosage information on this page is compiled from the following veterinary and pharmaceutical references:

  • Plumb's Veterinary Drug Handbook — the standard veterinary pharmacology reference used by veterinarians worldwide.
  • Merck Veterinary Manual — a trusted, peer-reviewed resource for veterinary professionals and pet owners.
  • DailyMed (FDA Drug Labels) — official FDA-approved drug labeling and prescribing information for Amlodipine.

Frequently Asked Questions

Why is high blood pressure dangerous in cats?
Uncontrolled hypertension in cats damages the eyes (causing sudden blindness from retinal detachment), kidneys (accelerating chronic kidney disease), heart (causing thickening of the heart muscle), and brain (causing seizures or disorientation). The most devastating and visible consequence is sudden blindness, which can be permanent if blood pressure is not quickly controlled.
How common is high blood pressure in senior cats?
Very common — studies show 20-65% of cats with chronic kidney disease (CKD) develop hypertension, and it frequently accompanies hyperthyroidism. All cats over 10 years old should have regular blood pressure checks, especially if they have kidney disease, thyroid disease, or diabetes. It is often called a "silent killer" because signs may not be obvious until organ damage occurs.
Can amlodipine restore vision in cats with hypertensive blindness?
If caught very early (within 24-48 hours of vision loss), rapidly lowering blood pressure with amlodipine can sometimes restore partial or full vision by allowing the detached retinas to reattach. However, if treatment is delayed, blindness is often permanent. This is why routine blood pressure screening in senior cats is so important.
How long does a cat need to take amlodipine?
Amlodipine is typically a lifelong medication, as feline hypertension is usually secondary to chronic conditions like kidney disease or hyperthyroidism that do not resolve. Regular blood pressure monitoring (every 3-6 months) ensures the dose remains appropriate as the underlying condition progresses.
Is amlodipine the only blood pressure medication for cats?
Amlodipine is the first-line and most effective antihypertensive for cats. It is significantly more reliable at lowering blood pressure in cats compared to ACE inhibitors (benazepril) or beta-blockers, which are often used in other species. In refractory cases, amlodipine may be combined with telmisartan (Semintra) for added effect.

Safety Resources