The intermediate-acting insulins are NPH, Purified Pork N, Hetin 2 NPH, Novolin N, Humulin NPH, Hetin 2 Lente, Novolin L (human), and Humulin L. These start working in 1 to 2 hours, with peak action in 4 to 12 hours. The pharmacokinetic duration of actlon is reported to be 24 hours (the shortest therapeutic action reported is 10 to 16 hours). (Note that the human NPH insulins have a therapeutic duration of action closer to 10 hours, while the pork or beef/pork Lente insulins have an action closer to 16 hours.)



Long-Acting Insulin

Long-acting insulin has been playing a newer role in the manage-ment of diabetes. This insulin-Ultralente-has more of what is termed a "flat curve." Instead of rising to a certain point and then dropping off, the action results in an elevated rise that remains for a long time before the effect is decreased. Since this duration may be greater than 24 hours, an overlapping effect creates a continuous blood level. The long-acting insulin is Ultralente (human). This insulin takes much longer to act (about 8 hours), peaks in about 18 hours, and has a pharmacokinetic action of 36 hours or more. Its therapeutic actions are about 18 to 24 hours. They are often used in the so-called "poor man's pump-management program." This is really a misnomer, but it is a useful term. The long-acting insulins are used for a basal insulin effect (a little insulin every so many minutes), with doses (called "boluses") of short-acting insulin given prior to each meal or large snack. This is a very effective way for some individuals to manage their diabetes. This regime is especially useful with Humalog insulin, which is ultrafast-acting and can be given with a meal instead of 30 minutes beforehand.

Premixed Insulin

Premixed insulins are now being used more frequently. Eli Lilly has a 70/30 human mixture (70 percent NPH and 30 percent R-Humulin 70/30), as does Novo-Nordisk (Novolin 70/30). Penfilled cartridges and prefilled cartridges are available. Ely Lilly also produces 50/50 insulin. Europe has other combinations of insulin in addition to 70/30 and 50/50. So far, the Food and Drug Administration has only approved the 70/30 and the 50/50 mixture in the United States .

Special Instruments for Insulin Administration

Equipment is available to assist the partially sighted or blind individual in reading the syringe (Insul-eze, Magni-Guide, and Syringe Magnified). These may be purchased either through the American Foundation for the Blind or directly from the manufacturer.

Instruments that aid in getting the appropriate dosage into the syringe are Adros IDM, Click-Count, Count-a-Dose, Dose-Aid, Insulgage, Holdease, Inject-Aid, Injection Safety Guard, Insulin Aid, Insulin Needle Guide, and Vial Center Aid. The Novolinpen also has clickers available to help in calculating the insulin dose.

Until there is a prevention or cure for diabetes, advances continue to be made in both the medications being used and the methods by which they are delivered.