Answers to general Vetsulin questions
What is Vetsulin?
The first and only insulin approved by the US Food and Drug Administration for treating canine diabetes mellitus. Vetsulin® (porcine insulin zinc suspension) is produced by Intervet/Schering-Plough Animal Health and is available only by prescription.
Is this a brand new insulin?
No, Vetsulin is registered in over 30 other countries as Caninsulin®. It was first registered in Australia in 1990, so there is over a decade of safety and efficacy history with this product.
Is Vetsulin made here in the US?
No, Vetsulin/Caninsulin are manufactured by Intervet/Schering-Plough Animal Health in Germany.
Can Vetsulin be kept at room temperature? Is it okay if Vetsulin is frozen?
No, Vetsulin should be kept refrigerated between dosing administrations. Vetsulin should not be frozen.
What type of insulin is Vetsulin?
Vetsulin is an intermediate-acting, lente insulin containing 40 IU per mL of highly purified porcine insulin. As a lente insulin, Vetsulin is an aqueous suspension containing 30% amorphous and 70% crystalline zinc crystals in a neutral buffer of pH 7.35.
Can Vetsulin be diluted?
No. Vetsulin is a mixture of amorphous (soluble) insulin and crystalline insulin. The crystalline part is relatively insoluble which is why the insulin activity lasts more than a few hours. Vetsulin has a balance between the amorphous and crystalline parts. If Vetsulin is diluted, the balance between amorphous and crystalline parts is no longer 30% and 70%, relatively speaking. The amount of soluble insulin is increased by the aqueous diluent used. This results in an alteration of the pharmacokinetics of Vetsulin. With a larger aqueous fraction and smaller crystalline fraction, there would be a decrease in the crystalline portion responsible for the second peak of insulin activity.
In addition, the stability of the suspension is unknown if Vetsulin is diluted. The Vetsulin suspension is optimized to maintain the crystalline portion as a salt. If the water content is increased as with dilution, the solution "looks for a new balance" ie, it is not stable and the dissolved fraction increases with time.
Can I use 100 IU syringes with Vetsulin?
No, use of a syringe other than a U-40 syringe will result in incorrect dosing. Using a U-100 syringe with Vetsulin would result in an animal receiving 2½ times less insulin than required. Human insulins are formulated at a concentration of 100 IU/mL. If clients use a U-40 syringe with a 100 IU insulin preparation, they would be injecting 2½ times the amount of insulin necessary, which could result in fatal hypoglycemia.
How does Vetsulin differ from human insulin products?
Vetsulin porcine insulin has the same amino acid sequence as natural canine insulin, whereas the commonly prescribed biosynthetic human insulin has a different amino acid sequence. Vetsulin’s similar structure may provide more effective regulation of blood glucose and decreases the risk of anti-insulin antibody development in dogs. While differences in amino acid sequencing can cause anti-insulin antibody formation in dogs and potentially lead to insulin resistance, anti-insulin antibodies are rare in cats.
For owners whose dogs or cats have been treated with human insulin, what differences or benefits could they see if their pets were treated with Vetsulin?
Vetsulin facilitates a more optimal treatment protocol than current human insulin products.
- Where biosynthetic human insulin is only available in 100 IU/mL concentrations, Vetsulin has a 40 IU/mL concentration allowing for more accurate dosing of small animals and reducing the risk of under- or overdosing.
- Vetsulin also comes in 2.5-mL vials—as well as the standard 10-mL vials—allowing more convenient dosing based on the size and needs of the pet.
- Vetsulin is administered with U-40 syringes, making it easier for the client to read the syringe.
What issues might a dog or cat encounter when switching from human insulin to Vetsulin?
Caution should be exercised when changing from one insulin product to another. Any change in insulin should be made cautiously and only under a veterinarian’s supervision. Changes in insulin strength, manufacturer, type, species (animal, human) or method of manufacture (rDNA versus animal-source insulin) may result in the need for a change in dosage.
How is Vetsulin distributed?
Vetsulin is purchased by clinics from distributors or directly from
Intervet/Schering-Plough Animal Health, which operates with a growing sales force in the United States. For more information, to place an order, or for technical support, call 800-441-8272 weekdays between 9 a.m. and 5 p.m. EST.
How long can Vetsulin be used once the vial has been broached?
For any insulin, it is recommended that vials in use be replaced with a new vial monthly.
Answers to questions about Vetsulin treatment in dogs
How does Vetsulin work in dogs?
A lente (intermediate-acting) form of insulin, Vetsulin contains 30 percent amorphous insulin for rapid onset of activity, usually peaking 4 hours after injection and lasting 8 hours. The remaining 70 percent of the formula is crystalline insulin which is absorbed more slowly and peaks around 11 hours after administration. The Vetsulin formula allows for a more continuous utilization of glucose to support the body’s basic functions. Vetsulin is administered subcutaneously once a day initially, although many dogs require twice-a-day administration for effective diabetes management.
What results typically can be expected from Vetsulin therapy in dogs?
Diabetic dogs in clinical trials responded to porcine insulin in the following ways:
- Substantially reduced mean 12-hour blood glucose concentration and mean blood glucose nadir post treatment, compared to pre-treatment levels.
- Reduced incidence of polyuria, polydipsia, and ketonuria in most dogs.
- Adequate blood glucose control in most dogs with less than one-third having hypoglycemic episodes.
How often does Vetsulin need to be administered in dogs?
Initially, the dose should be given once daily concurrently with or right after a meal. The veterinarian should reevaluate the dog at appropriate intervals and adjust the dose in 10% increments based on clinical signs, urinalysis results, and glucose curve/spot check values until adequate glycemic control has been attained. Twice-daily therapy should be initiated if the duration of insulin action is determined to be inadequate. If twice-daily treatment is initiated, each of the two doses should be 25% less than the once-daily dose required to attain an acceptable nadir.
The impact on blood glucose peaks may last from 14 to 24 hours, and approximately one in three diabetic dogs can achieve successful diabetes management with a single dose of Vetsulin per day. The treating veterinarian would need to determine the frequency of a patient’s dose.
Can Vetsulin really be used only once-a-day in dogs?
Clinical studies have demonstrated that approximately one-third of diabetic dogs can be maintained adequately on once-daily doses of Vetsulin. The other two-thirds of dogs will require twice-daily administration of Vetsulin.
How does Vetsulin differ from the human insulin products traditionally prescribed for diabetic dogs?
Vetsulin has the same amino acid sequence as natural canine insulin, whereas the commonly prescribed biosynthetic human insulin has a different amino acid sequence. Vetsulin’s similar structure may provide more effective regulation of blood glucose and decreases the risk of anti-insulin antibody development.
How many dogs currently have diabetes?
It is estimated that roughly 1 in 500 dogs suffers from the signs of diabetes mellitus. A recent market survey of more than 200 veterinarians showed that 70% had between one and 10 diabetic canine patients, while 26% noted that they had 11 or more diabetic canine patients.1
1. Vetsulin Veterinary Market Survey, 2004.
Answers to questions about Vetsulin treatment in cats
How does Vetsulin work in cats?
Vetsulin is a lente (intermediate-acting) form of insulin that contains 30 percent amorphous insulin for rapid onset of activity.
In cats, the peak activity following subcutaneous administration of Vetsulin occurs between 1.5 and 8 hours (with an average of about 4 hours1), and the duration of activity varies between 8 and 12 hours. This is why, in cats, Vetsulin is initially administered twice-daily rather than once a day.
1. Martin GJ, Rand JS. Pharmacology of a 40 IU/ml porcine lente insulin preparation in diabetic cats: findings during the first week and after 5 or 9 weeks of therapy. J Feline Med Surg. 2001;3(1):23–30.
What results typically can be expected from Vetsulin therapy in cats?
In the Vetsulin feline efficacy study used for FDA approval, cats were initially started on 1 to 2 IU of Vetsulin per injection twice daily. Glycemic control was evaluated based on blood glucose curves and clinical signs. Adjustment of the Vetsulin dose was made according to average blood glucose curve levels, blood glucose curve nadirs, and clinical improvement. At the end of the study, the Vetsulin dose ranged from 0 to 8 IU per injection twice daily.
Test cats demonstrated significantly lower blood glucose levels and a reduction in hyperglycemic clinical signs compared with pretreatment levels.
How often does Vetsulin need to be administered in cats?
In cats, the initial recommended dose is 1 to 2 IU per injection, and the injections should be given twice-daily (BID) at 12-hour intervals. So, unlike in the canine where initial dosing is based on body weight, dosing of Vetsulin in the feline is based on a per animal basis. The duration of activity of Vetsulin in the cat is shorter than in the dog, ranging between 8 to 12 hours. Peak activity level occurs between 1.5 to 8 (average of about 4) hours in the cat.
How many cats currently have diabetes?
Estimates of the incidence of diabetes mellitus in cats range from 1 in 100 to 1 in 500.
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