As most of you probably already know, ProZinc (PZI insulin), the only insulin preparation specifically made for use in diabetic cats (1,2), has been in short supply for the last few months (see my post about the shortage from last July). It turns out that the problem has been a shortage of protamine, the protein which slows down the absorption of the PZI insulin and increases its duration of action.
The company that manufacturers ProZinc, Boehringer Ingelheim Vetmedica, had to apply to the FDA for approval to continue to make the insulin using a new source of protamine. The GOOD NEWS is that the company has been granted approval for the insulin formula using the new supplier of protamine. They are now ramping up production of the new ProZinc, but there is a one-month timeline from production to release of an insulin product.
Despite the shortage, current market conditions are better than they have been in awhile. There is still about 4 to 6 weeks of inventory in distribution warehouses at this time. So if you have cats doing well on ProZinc, it should no longer be a problem to obtain the insulin as needed.
- Nelson RW, Lynn RC, Wagner-Mann CC, et al. Efficacy of protamine zinc insulin for treatment of diabetes mellitus in cats. J Am Vet Med Assoc 2001;218:38-42.
- Norsworthy G, Lynn R, Cole C. Preliminary study of protamine zinc recombinant insulin for the treatment of diabetes mellitus in cats. Vet Ther 2009;10:24-28.