ProZinc is the first and only protamine zinc recombinant human insulin product approved by the FDA specifically for the treatment of diabetes mellitus in cats. Manufactured by Boehringer Ingelheim, ProZinc has been a mainstay of feline diabetes management since its approval in 2009, offering veterinarians a purpose-built insulin formulated at a concentration designed for the small doses required by cats.
Overview
ProZinc is a 40 U/mL concentration insulin, meaning each milliliter contains 40 units of insulin — lower than the standard human 100 U/mL concentration. This lower concentration makes it easier to accurately measure the small doses typically needed by cats. The protamine zinc formulation provides a long duration of action, generally lasting 10 to 14 hours in cats, supporting twice-daily injection protocols. ProZinc must be used with U-40 insulin syringes to ensure accurate dosing.
Uses
- Feline diabetes mellitus — ProZinc is FDA-approved for reducing hyperglycemia in cats with diabetes.
- Cats newly diagnosed with diabetes — Often selected as a first-line insulin due to its veterinary-specific labeling and U-40 concentration.
- Cats requiring precise small-dose adjustments — The U-40 concentration allows finer dose titration than U-100 insulins.
Dosage
| Parameter | Detail |
|---|---|
| Starting dose | 1–2 U per cat subcutaneously every 12 hours |
| Typical maintenance | 1–4 U per cat every 12 hours |
| Concentration | 40 U/mL |
| Syringe type | U-40 insulin syringes only |
| Route | Subcutaneous injection |
| Frequency | Every 12 hours (twice daily) |
Important dosing notes:
- Always use U-40 syringes with ProZinc. Using U-100 syringes will result in a significant dosing error (underdose).
- Gently roll the vial between your palms before drawing up; do not shake vigorously.
- Administer injections at consistent 12-hour intervals, ideally at mealtimes.
- Dose adjustments should be guided by blood glucose curves performed by your veterinarian.
- If your cat does not eat, contact your veterinarian before giving insulin.
Side Effects
| Common Side Effects | Serious Side Effects (Contact Your Vet Immediately) |
|---|---|
| Mild injection site reactions | Hypoglycemia (weakness, trembling, seizures, collapse) |
| Transient decreased appetite during regulation | Diabetic ketoacidosis if undertreated |
| Weight changes | Somogyi rebound hyperglycemia |
Hypoglycemia is the most serious risk of insulin therapy. Signs include weakness, wobbling, tremors, disorientation, and seizures. If you observe these signs, apply corn syrup or honey to the gums and seek emergency veterinary care immediately.
Drug Interactions
- Corticosteroids (prednisolone, dexamethasone): Antagonize insulin action and worsen glycemic control.
- Progestins (megestrol acetate): Can induce insulin resistance in cats.
- Beta-blockers (atenolol): May mask signs of hypoglycemia such as tachycardia.
- Other hypoglycemic agents: Risk of additive hypoglycemia.
Provide your veterinarian with a complete list of all current medications and supplements.
Contraindications
- Do not administer during hypoglycemic episodes.
- Use with caution in cats with hepatic or renal impairment.
- Do not use if the insulin appears discolored, contains large clumps, or has been frozen.
- Safety has not been evaluated in breeding, pregnant, or lactating cats.
Storage
- Store unopened vials in the refrigerator (36–46 degrees F / 2–8 degrees C).
- Do not freeze.
- Once in use, store the vial in the refrigerator and discard after 60 days.
- Protect from direct sunlight and heat.
- Keep out of reach of children and pets.
FAQ
Q: Why does ProZinc use U-40 syringes instead of U-100? A: ProZinc is formulated at 40 U/mL, which is a lower concentration than standard human insulins (100 U/mL). This requires matched U-40 syringes to measure doses accurately. Using U-100 syringes with ProZinc will deliver less insulin than intended.
Q: How does ProZinc compare to insulin glargine for cats? A: Both are effective for managing feline diabetes. ProZinc has the advantage of being FDA-approved specifically for cats and comes in a U-40 concentration ideal for small feline doses. Glargine has been associated with higher remission rates in some studies. Your veterinarian will recommend the best insulin for your cat’s individual situation.
Q: Can my cat achieve diabetic remission on ProZinc? A: Yes. Some cats do achieve remission on ProZinc, particularly when combined with a low-carbohydrate diet. Your veterinarian will monitor blood glucose closely and reduce the dose gradually if remission occurs.
Q: What should I do if I miss a dose? A: If you miss a dose, give it as soon as you remember, but only if the next scheduled dose is at least 6 hours away. Never double dose. Contact your veterinarian for guidance.
This content is for informational purposes only and is not a substitute for professional veterinary advice. Always consult your veterinarian before starting, changing, or stopping any medication for your cat.