Last updated: Sat, 3 May 2008 19:56:37
It is now Fri, 25 Jul 2008 18:42:27
Last updated: Sat, 3 May 2008 19:56:37
It is now Fri, 25 Jul 2008 18:42:27
A Rose Is A Rose
A Unit Is A Unit
Photo by Almali
Most of the insulins you would buy at a pharmacy or from your veterinarian will be one of two concentrations. Concentration refers to the amount of biologically-active insulin relative to amount of fluid (suspension) in which the active insulin is dissolved or suspended.
Appropriately enough, these insulins are labeled, respectively, "U-40", or "U-100", and those labels should be on the vials of each.
Obviously, those two concentrations are very different, so if you're using a U-40 insulin (which has 40 units per milliliter), you will be injecting, relatively speaking, more fluid than you would if you were using a U-100 insulin (which has 100 units per milliliter).
The word "unit" can be very confusing! In one sense, it designates a specific amount of biologically-active insulin contained in the fluid in which it's dissolved, or, "suspended." This specific amount happens to be 1/22 milligrams of biologically-active insulin, which might be in crystalline form.
But suspensions differ from one manufacturer to another, one brand to another, of insulin. The suspension affects how the insulin is absorbed and used by the body. So, there is more to the make-up of one unit of insulin than merely its concentration.
The characteristics and the amount of suspension in which the biologically-active insulin is dissolved varies from one brand of insulin to another.
So there is more to a choice of insulin than just the concentration; the suspension makes a difference, too, and presumably your veterinarian takes that into account when prescribing for your dog (or cat).
Vekkie and I are anything but experts on the content of various formulas of insulin, but we got a general idea of the principles.
In this Merry Measures group of tales, we explore in slight depth and considerable playfulness, the meaning and significance of (International) Units of Insulin.
The only information contained in Vekkie's Merry Measure that can be said to be accurate is that concerning the concentration of U-40 or U-100 insulins, and the conversion factor if you decide to use syringes intended for U-100 insulins, with U-40 insulins.
All the rest is quite imaginary. Consult your veterinarian if you are treating a dog, or a cat, with insulin. If you want to use U-100 syringes - those marked specifically to measure U-100 insulin - with U-40 insulins, you need to learn the conversion, and to measure accordingly. That conversion is illustrated eventually in Vekkie's Merry Measures.
Syringes are marked to measure insulins of corresponding concentration, and if you get confused about just which markings on the syringe barrel mean what, you can kill your dog (or cat), by delivering too much insulin. You can do the same by delivering too little, though death will be slower in such an instance.
Please do NOT use the material here to make your own conversions, but check with your veterinarian and perhaps your pharmacist as eell
The name Vetsulin designates an insulin made by Intervet. In the United States, it is called Vetsulin, and in Canada, Europe, and probably some other places on Earth, it is called Caninsulin. It is specifically made for dogs, and is used for some cats as well, and perhaps with some other diabetic animals.
The name Novolin designates a U-100 insulin made by Novo Nordisk. This insulin is a U-100 insulin, made for humans. Quite a few veterinarians will prescribe for dogs, sometimes even cats, insulins made for humans. Many dogs, says my veterinarian, Dr. Amanda Booth, do really well on Novolin NPH insulin, and my Kumbi is living proof that can work well.
As a mnemonic device, Vekkie has shamelessly copied most of these two names to use as examples of U-40 or U-100 insulins. She calls her U-40 insulin "Vetsalin," and her U-100 insulin "Novalin". To prevent confusion, however, Vekkie has given Novalin a Passionate Pink color, and Vetsalin, a Glorious Green color.
Vekkie chose Novalin as her example of a U-100 insulin, rather than Humalin (the real stuff is called "Humulin"); simply because our Kumbi is receiving Novolin. Lilly's Humulin-N insulin is a U-100 insulin similar in many ways to Novolin NPH insulin. The real-world stuff has a slightly milky-white, cloudy appearance, with Novolin being somewhat more opaque than is Vetsulin (or its counterpart, Caninsulin).
Vekkie and I give special thanks to Muffins Jode and Rambo, Angie and Spud, and Marlene and Chelsea, for sending photographs that helped her get sorted out with her Merry Measures, insulins, and syringes. Also, to Bari and Angel for information on measurement markings on vials of Novolin and on BD U-100 syringes purchased in the United States.
Vekkie is working away at more Parts for the Parts List.
