How long will this bottle of insulin last?

Last year we discussed the typical cost of diabetes. We can expect diabetic pets to have at least an annual blood profile, rechecks, and evaluations of glucose curves even if they are uncomplicated diabetics. Some diabetics are more difficult to manage and get complications such as frequent urinary tract infections, perhaps episodes of pancreatitis, cataracts, and so forth. Clearly these issues can cost a lot in a hurry. And then there is the cost of the supplies…

This week I had a client ask about what syringe to get. She also wasn’t certain how long the bottle would or could be used once it was opened. She was concerned about the overall cost of supplies and how often she would need to buy a new bottle of insulin. Finally, she wanted to know if she could use any lancing device with her new glucose meter. She herself is diabetic and has a good understanding of the disease but was nervous as this was her beloved dog. She thought she was confused, but her logic was spot on. If this is confusing for one very smart lady, I’m betting others may have those same concerns.

Her vet just recently diagnosed her doggie with diabetes and started the dog on Vetsulin. Vetsulin is a u-40 insulin. That means there are 40 units per cc of insulin. Since there are 10 cc in a vial, that means there are 400 units in each vial. (40 units/cc x 10 cc = 400 units). Her vet started her dog on 5 units twice a day (which means a total of ten units over the course of each day). That bottle will last her dog 40 days. This of course is if he stays on this dose. We run glucose curves to evaluate a dose 5 to 7 days after starting or adjusting a dose.

Let’s try some other math to make sure you understand this. Let’s say a dog was on 5 units twice daily of NPH. NPH is u-100, meaning there are 100 units of insulin per cc. If we had a 10 cc bottle of U-100 NPH and had a dog taking 5 units twice daily, that bottle would last 100 days. (10 cc x 100 units/ cc = 1000 units. 1000 units divided by ten units total per day would mean 100 days, or a bit over 3 months before the insulin ran out.). Now, most vets recommend changing a bottle of most types of insulin at least every other month, so you would be discarding some of the insulin at this dose.

Let’s go back to our doggie on Vetsulin. What size syringe should she get? I’m a fan of the small volume syringes. These small volume syringes have a narrow barrel so the markings are more spread out along the syringe. It makes it easier to see! Her vet chose 1/2 cc U40 syringes for her. 1/2 cc x 40 units / cc means that syringe could contain up to 20 units of insulin. A one cc u-40 syringe could hold up to 40 units. We usually send 3/10 or 1/2 cc syringes with small pets, but your vet will do the math to find the right size (volume) syringe to best suit your pet.

Her last question is one I’ve heard lots of times. She wanted to know if she had to use the lancing device that came with her pet’s meter or if she could use one that had come with one of her own prior meters. Some folks think you need to use a specific lancing device for a particular meter. This is not the case. The lancets must fit whichever lancing device you choose, but a lancing device is simply a way to puncture the skin or mucus membrane to get a drop of capillary blood to use for a glucose reading. You can use whichever lancing device you wish. I personally like the ones with a clear top so I can aim for the marginal ear vein when I use that site. Some lancets actually fit into several devices.

Knowing how much to set aside for your pet’s diabetic supplies can be very helpful when sorting your budget. I hope today’s lesson simplified the matter.

NOTE: Consult your veterinarian first to make sure my recommendations fit your pets special health needs