Atenolol/Furosemide Transdermal Pen (9mL)

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.

This compounded formulation combines atenolol, a beta-blocker, with furosemide, a loop diuretic — two different drug classes. In compounding practice, clinicians may consider a combination like this for a multi-targeted approach. Your veterinarian determines whether it is appropriate based on your animal's diagnostic findings.

At a pharmacological level, this medication functions through two distinct mechanisms. Atenolol acts as a selective beta-1 adrenoreceptor antagonist, which slows the heart rate and may help address the force of cardiac contraction by blocking the effects of catecholamines like adrenaline. This allows for better ventricular filling and more efficient circulation. Furosemide acts by inhibiting the reabsorption of sodium and chloride in the thick ascending limb of the loop of Henle in the kidneys. This inhibition help address the signals that trigger water retention, leading to increased urine production and a decrease in the overall volume of fluid the heart must pump. Your veterinarian will determine the clinical appropriateness of this combination based on diagnostic findings, such as echocardiography, blood pressure monitoring and kidney health assessments.

This description reflects the general pharmacology of the active ingredient's drug class; your veterinarian determines whether this approach is appropriate for your animal.

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 of atenolol/furosemide administration include increased frequency of urination, increased thirst and localized digestive changes such as vomiting or a decrease in appetite. Because this medication influences heart rate and fluid volume, some pets may experience hypotension (low blood pressure) or dehydration, which can manifest as significant weakness or disorientation. Your veterinarian will monitor for shifts in electrolyte balance and renal parameters through periodic blood work to ensure the medication remains suitable for your pet's health status. Owners should watch for signs of persistent lethargy or unusual weakness and contact their veterinarian promptly if these behavioral shifts occur.

This medication is typically used with extra caution or avoided in patients with known severe renal impairment, electrolyte imbalances or pre-existing low blood pressure. It is also carefully evaluated in patients presented with an acute cardiac condition where certain beta-blockers may require precise timing for initiation. Sudden discontinuation of the atenolol component 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 medications your pet is receiving to avoid significant interactions, particularly with other heart medications or non-steroidal anti-inflammatory medications (NSAIDs).