Various types of veterinary insulins are known as PZI, "Protamine Zinc Insulin" . The ones we use most often for animals are a combination pork/beef-derived insulin or a beef-derived insulin. Because most are veterinary insulins, PZIs are not available at normal human pharmacies.
PZI veterinary insulins are intermediate-acting to long-acting, and can be closer in molecular structure to a cat or dog's own insulin than human-type or analog insulins. Veterinary PZI is a particularly good insulin type for cats. PZI is rarely used in dogs but is considered when other insulins are not effective.
NB:Animal-source insulins are becoming harder to make now, and PZIVet's recent discontinuation (see below) is likely the first in a tragic series that will make porcine and bovine-source insulins rare. We can hope that new GM insulins will shortly be introduced to make up the gap.In the meantime the alternatives include these other PZI insulins, and of course the human GM analogs Levemir and Lantus.
PZI itself was introduced in 1936; it was the first insulin having any type of suspension. Before PZI, the only insulin available was R/Neutral, having no additives to alter or extend its action. Until then, many with diabetes had to get up during the night to take an insulin injection because R/Neutral did not last long enough for an uninterrupted night's sleep .
Use and HandlingEdit
Cats tend to do well on PZI insulins. A 2001 study by Dr. Richard Nelson showed that 75% of previously treated hard-to-regulate cats did well with the insulin. He goes on to saythat most cats do require PZI twice daily. The other 25% of tested cats did not reach peak with PZI insulin until 9 hours + after injection; they would likely be able to use only one shot per day. As the study illustrates, absorption, peak and duration of PZI is variable.
According to the UK's National Health Service, in cases where a shorter-acting insulin is needed in addition to the PZI, the protamine zinc insulin must always be injected separately--NO mixing--due to the excess of protamine in the insulin formula.
PZI contains more zinc and protamine than NPH/isophane insulin and it is primarily the extra protamine which gives it its long-acting duration. The additional protamine in the suspension must first be broken down by proteolytic enzymes AKA proteases, before the insulin in PZI can be absorbed. NPH/isophane insulin contains less protamine than PZI does and because there's less, it is an intermediate-acting insulin.
No Combining For PZIEdit
Specifications of PZIEdit
British National Formulary defines protamine zinc insulin as a sterile suspension of insulin in the form of a complex obtained by the addition of a suitable protamine and zinc chloride.
Protamine Zinc Insulin
Sterile buffered suspension of mammalian insulin to which protamine and zinc chloride are added. White suspension. pH 6.9 - 7.5 iso-osmotic with blood. Contains for each 100 units of insulin, 1 - 1.7 mg of protamine sulphate and zinc chloride equivalent to 200 per g of zinc, 10 - 11 mg of sodium phosphate.
Protamine Zinc Insulin
Buffered sterile suspension to which zinc chloride and protamine sulphate are added. 40, 80, 100 units/ml. Also contain glycerol, cresol, phenol, sodium phosphate for each 100 units of insulin in addition to protamine and zinc.
Types of Veterinary PZIEdit
These are manufactured, not compounded, insulins. This means the insulin keeps longer, and is less likely to vary, as compounded insulins can, from batch to batch. The manufactured insulins (except ProZinc) have a shelf life of three years (unopened).
ProZinc™EditProZinc™ (protamine zinc recombinant human insulin) isBoehringer Ingelheim Vetmedica's replacement for PZI Vet insulin. Boehringer Ingelheim Vetmedica was the purchaser of the PZI Vet franchise from IDEXX. ProZinc is a manufactured (not compounded) U-40 insulin with FDA approval for use in diabetic cats. Dosing is expected to be similar to PZI Vet insulin. According to a BIV technical representative, during efficacy trials cats were switched from PZI Vet insulin to ProZinc in a 1:1 dosing ratio and they did "well." It comes in 10ml bottles and has a shelf life of two years from the date of manufacture. Like other insulins it must be kept refrigerated. Generally ProZinc should be given twice a day. It's characteristics (onset, peak, duration etc.) should approximate if not mirror the old PZI Vet insulin. Since this is a new insulin [Nov 2010] and the supply is on "allocation," supplies may be limited during the immediate future. It is available online, though some vets and some pharmacies.
PZI Vet (IDEXX) EditPZI Vet was made by IDEXX Laboratories (formerly Blue Ridge). PZI Vet is a
beef/pork PZI insulin commonly used in diabetic cats in the U.S. Some compounding pharmacies may
refer to their PZI insulins as PZI Vet, but you aren't using PZI Vet. unless it is made by IDEXX Labs. Unlike the other PZI's below, PZI Vet is a mix of beef and pork insulin. Beef insulin is closest to a cat's own insulin, and pork is identical to a dog's. PZI Vet is a manufactured insulin; the formula is that of Lilly's 90% beef/ 10% pork Iletin I Protamine Zinc insulin; Blue Ridge purchased it from Eli Lilly after the firm discontinued it.
Note: IDEXX PZI is being discontinued shortly due to animal insulin supply problems:
April 8, 2008 Dear Concerned Cat Owner, Recently there have been some developments regarding the availability of PZI VET® (protamine zinc insulin), and I wanted to update you on the situation because it may impact your diabetic cat. You may know that PZI VET is derived from bovine and porcine pancreatic glands, and unfortunately, the supply of our original raw material has been exhausted. As there are no FDA approved facilities for harvesting bovine pancreatic tissue, we have determined after extensive study that further production of animal source insulins is not practical in a modern manufacturing environment. Therefore, following the sale of our existing inventory, IDEXX will no longer manufacture or sell any animal-based insulin. We are currently in the process of notifying veterinarians who prescribe PZI-VET of the situation. As of April 1, 2008, there was a considerable inventory in distribution, so please consult with your own veterinarian on the best course of action for your cat. We appreciate that feline diabetes is a chronic condition requiring ongoing treatment and monitoring. Accordingly, IDEXX remains committed to the treatment of this disease. We are working diligently to develop and bring to market a new insulin product for the treatment of diabetes in cats. Sincerely, Cynthia Cole DVM, PhD, DACVCP Manager, Professional Services Group IDEXX Pharmaceuticals, Inc.
Insuvet PZI EditInsuvet Protamine Zinc or Insuvet PZI is a PZI from Insuvet, similar to BCP's PZI above. Insuvet also makes two other veterinary insulins.
Schering-Plough Animal Health contracted CP Pharma to produce its Insuvet line of bovine insulins. The Insuvet line was sold to Pfizer Animal Health and it is believed that Pfizer continues to contract CP/Wockhardt UK for their production. Some UK pet pharmacies offer both the Insuvet-branded and the Hypurin-branded insulins. The only difference here may be pricing.
Insuvet insulins are only available in the UK; the option for those in other countries is either importing from CP Pharma or, if you are in North America, the compounded PZI in various strengths available from BCP and VPOA (US) and Summit (Canada).
CP Pharma EditHypurin Bovine Protamine Zinc is a U100 100% bovine PZI manufactured by CP Pharma. It is approved for use in humans and can be imported into the US and other countries.
CP Pharma also produces Hypurin Vet Protamine Zinc, which is pure beef but not offered outside of the UK.
CP Pharma actually produced the Schering-Plough Animal Health Insuvet insulins. After the Insuvet line was sold to Pfizer Animal Health, it's believed that Pfizer still contracts CP/Wockhardt UK for their production.
Compounded insulins typically have shorter lifespans and there are fewer quality controls in place than with manufactured insulins to ensure the highest consistency insulin reaches the consumer.
Specialty Veterinary Pharmacy in Houston, TX, USA, Compounds (40u and 100u) PZI insulin (pure BEEF)
www.svpmeds.com Phone 1-877-673-3705
BCP PZI Edit
BCP PZI is a bovine-origin PZI-based insulin. Because it's beef based, its amino acid chain is almost the same as that of a cat, so it's especially well-matched to cats.
BCP Veterinary Pharmacy in Houston, TX, USA, manufactures and is the sole source supplier for BCP PZI. BCP PZI is commonly used in diabetic cats in the U.S. BCP PZI is a compounded insulin. Now that other pharmacies are discontinuing their bovine insulin, BCP Veterinary Pharmacy will most likely be the sole producer of Pure Beef PZI insulin in the U.S.
VPOA PZI Edit
BCP, VPOA, and other compounding pharmacies are the only US source for pure beef insulin of any type. Manufactured beef insulins must be imported from CP Pharma.
UK, Canada, and US-other compounded PZIs Edit
Those in Canada can obtain 100% beef compounded PZI in U100 strength from Summit Veterinary Pharmacy in Ontario. Summit sells their insulin solely through vets--yours will need to place the order for you.
There are also pharmacies in the US and UK that compound PZI based on human ("regular") or animal-source insulins. It is possible to have PZI Humulin insulin of any strength compounded at some local compounding pharmacies: this relatively inexpensive route has produced satisfactory results for some cats.
Your vet may also be able to obtain manufactured PZI insulin for you through Health Canada's Emergency Drug Release program. With it, you are able to receive up to 6 months worth of insulin; a C$ 50.00 fee for the application is required . If permitted, you would then be eligible to import PZI insulins such as PZI Vet,Insuvet Protamine Zinc, Hypurin Vet Protamine Zinc, or Hypurin Bovine Protamine Zinc, as well as the other insulins Insuvet and CP Pharma produce.
The program is similar to Health Canada's Special Access Programme  for importing necessary drugs for people.
- Wiki cases--Feline PZI users
- Wiki cases--Feline PZI Vet users
- Wiki cases-Feline BCP PZI users
- Wiki cases--Feline Insuvet PZI users
- Wiki cases--Feline Hypurin Vet PZI users
- Wiki cases--Feline Compounded PZI users
- Insulin Therapy in Cats With Diabetes Mellitus-JAVMA-1983
Contains peak, onset, duration data for NPH/isophane & PZI insulins in cats.
- Comparison of 2 Ultralente Insulin Preparations With Protamine Zinc Insulin in Normal Cats-American Journal of Veterinary Research-1994
- Absorption Kinetics of Regular (Neutral), Isophane (NPH) and Protamine Zinc Insulin (PZI) in Normal Cats-Domestic Animal Endocrinology-1990
- Insulin Therapy in Cats with Diabetes Mellitus-JAVMA-1983
Some feline Time Activity information on NPH/isophane & PZI insulins.
- Clinical Study Evaluating & Comparing Recombinant PZI With Bovine/Porcine PZIVet-ACVIM 2008-Oral Presentations-Page 30, Abstract #97 & #98
- List of sources and prices for PZI insulins worldwide
- BCP Contact information
- Characteristics of Animal Insulins
- Protamine Zinc insulin information--InChem
- Some Rules for Dosage of Protamine Zinc Insulin-Canadian Medical Association Journal 1938
This dates back to 2 years after PZI was introduced. Though these are human experiences, it may provide some insight into using pure beef PZI. "Unmodified Insulin" referred to is today's R/Neutral type.
Insights like this liven things up aornud here. Insights like this liven things up aornud here.
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