Q & A: Vetsulin Insulin Discontinued, Now What Insulin?

I have a 10-year-old male neutered diabetic chihuahua that was diagnosed after Vetsulin went off the market.  We tried for several months to regulate him on Humulin N, but we never could get him controlled.  

We finally got him enrolled in the Vetsulin Critical Need Program.  He is doing great on Vetsulin given twice daily, but now we're unable to get any more of the Vetsulin.  As you know, the Vetsulin Critical Need's Program has been discontinued!

Now that that honeymoon is over, what insulin can I try on this problem diabetic?

My Response:

Vetsulin (Lente insulin) is actually a mixture of rapid-acting and long-acting insulins (Semi-lente and Ultralente). So knowing that your patient responded better to the Vetsulin, you have 3 'general' choices for selecting the next insulin preparations in this dog. I do not believe that Vetsulin will be returning to the market anytime soon. You also know from past experience that human NPH isn't a good choice for this diabetic patient.

Humulin 70/30 (Eli Lilly) may be a good choice in this dog. This is a 100 U/ml pre-mixed combination of 30% short-acting and 70% intermediate-acting insulin. Because it has a similar duration/action curve to Vetsulin, Humulin 70/30 insulin is well suited to a twice-daily dosing regimen in diabetic dogs where meals are fed at the same time as the insulin injections.

Another insulin choice similar to Humulin 70/30, is a pre-mixed combination of a short-acting synthetic insulin analogue (ie, Lispro or Aspart insulin) with a longer-acting insulin analogue (ie. Lispro or Aspart Protamine Insulin). Examples of these synthetic insulin combinations include Humalog Mix 75/25 (Eli Lilly) or NovoLog 70/30 (Novo Nordisk).  Both of these insulin analogue mixtures are given twice daily with meals.

Finally, my third choice is detemir insulin (Levemir, Novo Nordisk). This is another insulin analogue with a long duration of action with a similar action profile to glargine (Lantus), but detemir appears to be more potent and work better in dogs than than glargine does.   Detemir is the most potent of these insulin choices and is dosed initially at  0.1 U/kg BID, again generally administered at time of feeding.