Insulin Formulations and Concentrations

Understanding insulin formulations and concentrations will help you treat your pet's condition. Using the wrong concentration or incorrectly calibrated syringes can be fatal. Below, you will find good information about formulations and concentration of insulin. As always, if you have questions, contact your veterinarian.

The three insulin formulations are: Short Acting, Intermediate Acting and Long Acting.

Short Acting
Rapid onset of activity

• quite potent in nature
  
• used primarily in emergency situations - diabetic ketoacidosis
• Regular insulin - most commonly used in vet med. Time to peak activity 1-5 hours and a duration of 4-10 hours.

• similar to time to peak activity in both dogs and cats with duration of activity typically longer in dogs than in cats
• *NPH (Isophane) + Lente (Zinc) - most common preparations used. This is the most common type of insulin used in canine patients

• Long Acting insulins are typically the least potent
• In theory, the long acting insulin can be administered once daily
• Each individual animal will respond differently
• PZI or Ultralente insulin is the most common insulin cats start on for therapy

• U-100 which measured out to 100 units of insulin per milliliter or cubic cm (ml or cc)
• U-40 which is measured out to 40 units of insulin per ml or cc
• syringes are manufactured to be used with the appropriate insulin concentration, i.e., u-100 syringes with u-100 insulin and u-40 syringes with u-40 insulin
• Very important to make sure you are using the appropriate syringe with the appropriate insulin.

What preparation is best for my pet?
For dogs: Lente and NPH are used most commonly for long term therapy
*starting dose for dogs ranges between .5-.75 units/kg (kilogram) body weight at twice daily intervals
- larger dogs initially receive doses on the lower end of the range while smaller dogs are typically started on the higher end of the range.

For cats: Good glycemic control is most commonly achieved by twice daily dosing with insulin rather than once daily.
If once daily dosing is the only option PZI at 1-3U/cat appears to be the best options for adequate control. PZI (PZI VET - IDEXX Labratories)

* Newly Diagnosed Diabetic Patients that are stable (eating, drinking and not vomiting) can be started on home insulin therapy.
It is recommended that a glucose curve be performed about 7-14 days after your pet has been started on insulin to determine its response to the initial dose.