Calcium channel blocker (antihypertensive)
⏱ Onset: 1-2 hours; full effect in 1-2 weeks
⏳ Duration: 24 hours
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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.
Dosage Calculator
Enter your cat's weight to calculate the recommended dose.
Recommended Dosage
Low Dose
—
mg
Standard Dose
—
mg
Max Dose
—
mg
Frequency
once daily
💊 Closest Tablet
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These calculations are estimates based on standard veterinary dosing guidelines. Always confirm with your veterinarian before administering medication.
Norvasc Dosage Chart for Cats by Weight
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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
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.