Felis ISSN 2398-2950


Synonym(s): Caninsulin, Vetsulin, ProZinc, Lantus, Levemir

Contributor(s): Linda Horspool



  • Insulin.

Class of drug

  • Polypeptide hormone or analog of polypeptide hormone.


Physical properties

  • Suspension (not for intravenous administration) or clear solution, depending on formulation.
  • Insulin exists as monomers at low concentrations and aggregates into stable dimers at higher concentrations, in aqueous solution at pH 2-8, and into hexamers in the presence of zinc ions. Zinc is used in the formulation of insulin to extend its duration of action.

Storage requirements

  • Should be stored in refrigerator prior to opening.
  • Store refrigerated; some products may be kept at room temperature (<25°C) after first opening.
  • Sterile products - usually should be used for no more than 28 days after first opening, some products may be kept at room temperature (<25°C) for this period.
  • Do not freeze.
  • Protect from light.


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  • For the reduction of hyperglycemia and hyperglycemia-associated clinical signs in cats with diabetes mellitus Diabetes mellitus.
  • Occasionally as adjunctive therapy in the management of hyperkalemia Hyperkalemia.


  • Ultra-rapid, rapid, intermediate and long-acting formulations are available. Ultra-rapid acting insulin analogs (eg insulin aspart) are not used routinely in veterinary species due to the risk of hypoglycemia but have been used for intensive treatment of diabetic ketoacidosis Diabetic ketoacidosis after fluid replacement.
  • Regular (soluble, neutral) insulin is a clear, colorless, aqueous solution buffered at neutral pH (7-7.8). It contains human recombinant insulin (100 IU/mL) and zinc, which slows its absorption. It has a rapid (<1 h) onset of action, peak effects 1-4 h after administration and a short duration of action (<8 h) after SC administration. Used under close veterinary supervision where a rapid effect is required (eg in the management of diabetic ketoacidosis).
  • Intermediate and long-acting formulations generally need to be administered twice daily to diabetic cats to provide adequate glycemic control.
  • Porcine insulin zinc suspension (40 IU/mL, Caninsulin or Vetsulin) is approved for use (40 IU/mL) in dogs and cats. A lente insulin containing a mixture of amorphous zinc (semilente, c. 30%) and long-acting crystalline zinc (ultralente, c. 70%) insulin suspensions to provide rapid onset (<2 h), peak action around 4-8 h after SC administration and duration of activity of 8-12 h in cats. Twice daily administration is required in cats.
  • Neutral protamine Hagedorn (NPH) insulin (100 IU/mL) is an aqueous suspension buffered at pH 6.9-7.5. It contains crystalline zinc human recombinant insulin and the basic (positively charged) poly-arginine peptide protamine. Its duration of action is usually too short to be useful in cats. Not approved for veterinary use.
  • Protamine Zinc Insulin (40 IU/mL, ProZinc) contains crystalline zinc insulin and protamine to provide rpeak action around 3-9 h after SC adminstration and duration of activity of at least 9 h in most cats. Twice daily administration is required in cats. Approved for use in cats.
  • Insulin glargine Insulin glargine is a basal analog of human insulin where asparagine at A chain position 21 is replaced with glycine and arginine added to B chain positions 31 and 32. Insulin glargine requires twice daily administration in veterinary species to provide adequate glycemic control. Used commonly in diabetic cats but can have variable duration of action (8-24 h). Insulin glargine is not approved for use in veterinary species.
  • Insulin detemir Insulin detemir is a basal analog of human insulin where threonine is omitted from B chain position 30 and a 14 carbon fatty acid chain attached to lysine at B chain position 29. Insulin detemir is not approved for use in veterinary species (100 IU/mL).


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with other drugs

Drugs which may antagonize the blood glucose lowering effects of insulin

Drugs which may increase the effects of insulin

  • Anabolic steroids.
  • Beta-adrenergic blockers, (eg propranolol propranolol).
  • Ethanol Ethanol.
  • Phenylbutazone.
  • Salicylates.
  • Tetracycline Tetracycline.

Adverse Reactions

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Further Reading


Refereed papers

  • Recent references from VetMed Resource and PubMed.
  • DiFazio J & Fletcher D J (2016) Retrospective comparison of early- versus late-insulin therapy regarding effect on time to resolution of diabetic ketosis and ketoacidosis in dogs and cats: 60 cases (2003-2013) J Vet Emerg Crit Care (San Antonio) 26, 108-115 PubMed.
  • Hoelmkjaer K M, Spodsberg E M & Bjornvad C R (2015) Insulin detemir treatment in diabetic cats in a practice setting. J Feline Med Surg. 17, 144-151 PubMed.
  • Sparkes A H, Cannon M, Church D, Fleeman L, Harvey A, Hoenig M, Peterson M E, Reusch C E, Taylor S & Rosenberg D (2015) ISFM consensus guidelines on the practical management of diabetes mellitus in cats. J Feline Med Surg 17(3), 235-250  PubMed.
  • Gostelow R, Forcada Y, Graves T, Church D & Niessen S (2014) Systematic review of feline diabetic remission: Separating fact from opinion. Vet J 202(2), 208-221 PubMed.
  • Caney S M (2013) Management of cats on Lente insulin: tips and traps. Vet Clin North Am Small Anim Pract 43, 267-282 PubMed.
  • Gilor C & Graves T K (2010) Synthetic insulin analogs and their use in dogs and cats. Vet Clin North Am Small Anim Pract 40, 297-307 PubMed.
  • Rucinsky R, Cook A, Haley S, Nelson R, Zoran D L & Poundstone M (2010) AAHA Diabetes management guidelines for dogs and cats J Am Anim Hosp Assoc 46, 215-224 PubMed.
  • Zini E, Hafner M, Osto M, Franchini M, Ackermann M, Lutz T A & Reusch C E (2010) Predictors of clinical remission in cats with diabetes mellitus. J Vet Intern Med 24, 1314-1321 PubMed. Article.
  • Nelson R W, Henley K, Cole C; PZIR Clinical Study Group (2009) Field safety and efficacy of protamine zinc recombinant human insulin for treatment of diabetes mellitus in cats. J Vet Intern Med 23, 787-793 PubMed
  • Michiels L, Reusch C E, Boari A, Petrie G, Mandigers P, Thollot I G, Rosenberg D, Mooney C, Bonfanti U, Font A, Sparkes A, Bewig K, Clercx C, Jensen A L, Horspool L J (2008) Treatment of 46 cats with porcine lente insulin--a prospective, multicentre study. J Feline Med Surg 10, 439-451. PubMed
  • Martin G J & Rand J S (2007) Control of diabetes mellitus in cats with porcine insulin zinc suspension. Vet Rec 161(3), 88-94 PubMed.
  • Weaver K E, Rozanski E A, Mahony O M, Chan D L & Freeman L M (2006)Use of glargine and lente insulins in cats with diabetes mellitus.J Vet Intern Med 20(2), 234-248 PubMed.

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