Atenolol Transdermal Pen (6mL)

A transdermal pen is a simple way to give your pet medicine through their skin—usually used for cats by applying gel to the inside of their ear.

Step-by-Step:

1. Get the pen ready – Twist the pen to dispense a small amount of gel. If it’s your first time, you will need to “prime” it first (the gel should be flush with the edge of the tip)
2. Wear gloves – Always use a disposable glove or finger cot so the medication doesn’t absorb into your skin.
3. Twist to dose – Follow the pen’s directions (like two full twists) to get the right amount of gel out. Always click in a clockwise direction, clicking counter-clockwise will stop you
4. Pick the spot – Apply to a hairless area, usually the inside of your cat’s ear. Make sure the area is clean and dry.
5. Apply the gel – Dab the gel directly with the pen or use your gloved finger to rub it in gently. Avoid the ear canal.
6. Let it dry – It usually dries in a minute or two. Try to keep your pet from rubbing it off.
7. Recap the pen – This keeps the medication fresh.
8. Wash your hands – Even if you wore gloves, wash thoroughly after.
9. Reward your pet – A treat helps make it a stress-free routine!
10. Store properly – Keep at room temp, away from sunlight. Track doses so you know when it’s time to refill.

Important: Only apply where your vet has directed—usually hairless areas. Never apply over fur or broken skin. Keep other pets from licking the area until it’s dry.

The uses and pharmacology described below reflect the FDA-approved labeling for this active ingredient; your veterinarian determines whether and how they apply to your animal's treatment plan.

Veterinarians most commonly consider atenolol when a patient is presented with tachyarrhythmias (abnormally fast heart rates), such as supraventricular tachycardia or when managing systemic hypertension. It is frequently a point of discussion for cardiovascular health in feline patients with hypertrophic cardiomyopathy (HCM), where the objective is to modulate heart rate to allow for better ventricular filling. By addressing the frequency of electrical impulses and the force of cardiac contraction, your veterinarian can manage the physiological workload placed on the heart.

At a pharmacological level, atenolol acts by selectively blocking beta-1 adrenergic receptors located primarily in the cardiac muscle. This blockade inhibits the effects of catecholamines, such as epinephrine and norepinephrine, which normally increase heart rate and blood pressure. Because it is beta-1 selective, atenolol has a minimal influence on the beta-2 receptors found in the bronchial and vascular smooth muscle at standard doses, making it a common choice for pets with concurrent airway sensitivities. Your veterinarian will determine the clinical appropriateness of this medication based on diagnostic findings such as echocardiography or electrocardiograms (ECG).

Prescription only. Use only under the direction of a licensed veterinarian. This information is not a substitute for veterinary diagnosis, prescribing or monitoring. Compounded drugs are not approved by the FDA for safety or effectiveness.

Commonly observed effects following the administration of atenolol include lethargy, a decrease in activity level or localized digestive changes such as vomiting or loose stools. Because the medication influences cardiac output, some pets may experience bradycardia (an abnormally slow heart rate) or hypotension (low blood pressure), which can manifest as significant weakness or disorientation. Your veterinarian will monitor your pet closely during the initiation of therapy to ensure the heart rate remains within a targeted clinical range. Owners should watch for signs of extreme tiredness or fainting and contact their veterinarian promptly if these occur.

This medication is typically used with extra caution or avoided in patients with known congestive heart failure, certain types of heart block or severe renal impairment. It is also carefully evaluated before use in pets with asthma or other obstructive airway diseases, as high doses may lose beta-1 selectivity. Sudden discontinuation of atenolol can lead to a "rebound" effect, potentially worsening heart rhythm issues; therefore, any adjustments to the protocol must be directed by a professional. Before starting any new prescriptions, ensure your veterinarian has a complete history of all other supplements or medications your pet is receiving to avoid significant interactions.