|Background Information about Insulin
When we eat, our bodies break food down into organic compounds,
one of which is glucose.
The cells of our bodies use glucose as a source of energy
for movement, growth, repair, and other functions. But before the cells
can use glucose, it must move from the bloodstream into the individual
cells. This process requires insulin.
Insulin is produced by the beta cells in the islets of
Langerhans in the pancreas. When glucose enters our blood, the pancreas
should automatically produce the right amount of insulin to move glucose
into our cells. Canines with type 1 diabetes produce no insulin. Felines
with type 2 diabetes do not always produce enough insulin. (Felines can
be type 1 or 2 and Canines are always type 1)
- NPH cannot be mixed with any Lente (L or U) insulin,
they are chemically incompatible.
- Insulin does not have to be refrigerated if kept at
a moderate temp., although it is recommended.
- Do not give cold injections, it could cause discomfort.
- Popular opinion is to dispose of opened insulin after
30 days or 100 sticks.
- To prevent abscesses, infections, and discomfort, only
use syringes once.
- Rotation of injection sites is recommended.
- It is best to feed before the injection to make sure
the animal eats. (generally 30 min. before)
- Human insulins are shorter acting than animal insulins
of the same type.
- Never shake "cloudy" insulins. Roll the bottle between
the palms of your hands.
Duration and Peak Times for the Most Common Insulins
Types of Insulin
There are more than 20 types of insulin products available
in four basic forms, each with a different time of onset and duration of
action. Plus you have caninsulin, vetsulin and pzi for animals. . The decision
as to which insulin to choose is based on a veterinarian's preference and
experience, and the canine's blood sugar levels. Among the criteria considered
in choosing insulin are:
how soon it starts working in (onset)
when it works the hardest (peak time)
how long it lasts in the body (duration)
The following table lists some of the more common insulin
preparations available today. Onset, peak, and duration of action are approximate
for each insulin product, as there may be variability depending on the
animal, the injection site, exercise. The key to regulation is consistency!
||Starts in (onset)
||Peaks in (nadir)
||Gone by (duration)
IS NOT BEING
|Intermediate and short-acting mixtures
Humalog Mix 75/25
Humalog Mix 50/50
Novolog Mix 70/30
with little peak
||6 hours (slight)
with little peak
These are only averages, each pet reacts differently to their insulin.
Another graph showing duration and peak times of some insulins
Vetsulin is now available in the United States.
For more information visit their website
PZI stands for protamine zinc insulin. This is insulin combined with large
quantities of a protein called protamine. This protein slows the absorption
of insulin from a subcutaneous site. These preparations have a long duration
of action, but might sometimes have the problem of poor insulin absorption
that also occasionally affects ultralente preps. PZI can be formulated
for any species of insulin. In the UK, the veterinary licensed PZI is bovine.
Peter A. Graham
Efficacy of protamine zinc insulin(PZI) for treatment
of diabetes mellitus in cats.
Nelson RW, Lynn RC, Wagner-Mann CC, Michels
Department of Medicine and Epidemiology, School
of Veterinary Medicine, University of California, Davis 95616, USA.
to the article
OBJECTIVE: To evaluate effects of protamine zinc insulin (PZI)
on control of glycemia in cats with newly diagnosed diabetes mellitus or
poorly controlled diabetes.
DESIGN: Clinical trial.
ANIMALS: 67 diabetic cats.
PROCEDURE: 34 cats with newly diagnosed diabetes and 33 cats
with poorly controlled diabetes were treated with PZI twice daily for 45
days. Control of glycemia was assessed on days 7, 14, 30, and 45 by evaluation
of clinical response, change in body weight, serum fructosamine concentration,
blood glucose concentration measured 1, 3, 5, 7, and 9 hours after administration
of PZI, lowest blood glucose concentration, and mean blood glucose concentration
during the 9-hour period after administration. Adjustments in dosage of
PZI were made as needed to attain control of glycemia.
RESULTS: For all cats, a significant increase in mean dosage
of PZI and significant decreases in 9-hour mean blood glucose concentration,
lowest mean blood glucose concentration, and mean serum fructosamine concentration
were detected. For cats with poorly controlled diabetes, 9-hour mean blood
glucose concentration and mean serum fructosamine concentration were significantly
decreased on day 45, compared with day 0. Ninety percent of owners reported
improvement or resolution of clinical signs by day 45.
CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that PZI
was effective for control of glycemia in cats with newly diagnosed or poorly
controlled diabetes and may be used as an initial treatment or as an alternative
treatment in cats that do not respond to treatment with other types of
Lantus insulin is now being used for cats with some success.
PZI and Lantus (insulin for
felines both have about the same action)
* 0.25 units per pound twice a day for BG numbers 360 or greater and
0.10 Units per puund for BGs less than 360.
For a 10 pound cat 2.50 units twice daily for
blood glucose greater than 360
For a 15 pound cat 3.75unit twices daily for
blood glucose greater than 360
For a 15 pound cat 1.50 units twice daily for blood glucose less than
For a 10 pound cat 1.00 unit twice daily for blood glucose less than
* PZI and Lantus should be kept in the refrigerator (always look at
* Opened vials of PZI have a shelf life of 30-90 days and Lantus 30
(home testing will help you best determine effectiveness)
* U-40 syringes for PZI and U100 syringes for Lantus
* PZI syringes can be purchased on-line without a prescription at http://hocks.com
*Lantus need a prescription.
A study on three insulins in cats. glargine is another name for lantus
Marshall RD, Rand JS, Morton JM.
Centre for Companion Animal Health, School
of Veterinary Science,
The University of Queensland, Brisbane, Australia,
and The Cat Clinic,
Mt Gravatt, Brisbane, Australia.
to the article
The pharmacological effects of glargine, protamine zinc (PZI), and
lente insulins were evaluated in nine healthy cats. A 3-way crossover study
was performed and plasma concentrations of insulin and glucose were determined
for 24 h after a single subcutaneous injection of each insulin at 3-day
intervals. Time to onset of action did not differ between insulins. Mean
time to first nadir glucose was longer for glargine (14 h) relative to
PZI (4 h) and lente (5 h). PZI was biphasic in action with nadirs at 4
and 14 h with the second nadir occurring at a similar time to glargine.
Nadir glucose did not differ significantly between insulin types. The duration
of action was similar for glargine and PZI and was longer than that for
lente insulin. Mean daily glucose after glargine and PZI were also similar
and were lower than after lente insulin. Time to reach peak insulin did
not differ between insulin types. Time to return to baseline insulin level
for PZI was longer than glargine but did not differ significantly from
lente. In conclusion, healthy cats injected subcutaneously with glargine,
compared to those injected with lente insulin, have a later glucose nadir
and longer duration of action. Glargine and PZI had similar durations of
action in study cats but a larger study is required to obtain precise comparisons
of duration of action.
Use of glargine and lente insulins in cats
with diabetes mellitus.
Weaver KE, Rozanski EA, Mahony OM, Chan DL,
Department of Clinical Sciences, Cummings School of Veterinary Medicine,
Tufts University, North Grafton, MA 01536, USA.
to the article
The goals of this study were to compare the efficacy of once-daily
administered Glargine insulin to twice-daily administered Lente insulin
in cats with diabetes mellitus and to describe the use of a high-protein,
low-carbohydrate diet designed for the management of diabetes mellitus
in cats. All cats with naturally occurring diabetes mellitus were eligible
for inclusion. Baseline testing included a physical examination, serum
biochemistry, urinalysis and urine culture, serum thyroxine concentration,
and serum fructosamine concentration. All cats were fed the high-protein,
low-carbohydrate diet exclusively. Cats were randomized to receive either
0.5 U/kg Lente insulin q12h or 0.5 U/kg Glargine insulin q24h. Re-evaluations
were performed on all cats at weeks 1, 2, 4, 8, and 12, and included an
assessment of clinical signs, physical examination, 16-hour blood glucose
curve, and serum fructosamine concentrations. Thirteen cats completed the
study (Lente, n = 7, Glargine, n = 6). There was significant improvement
in serum fructosamine and glucose concentrations in all cats but there
was no significant difference between the 2 insulin groups. Four of the
13 cats were in complete remission by the end of the study period (Lente,
n = 3; Glargine, n = 1). The results of the study support the use of once-daily
insulin Glargine or twice-daily Lente insulin in combination with a high-protein,
low-carbohydrate diet for treatment of feline diabetes mellitus.