What are the types of insulin for diabetes treatment?

The types of insulin include:

• Rapid-acting insulin, such as insulin lispro (Eli Lilly), insulin aspart (Novo Nordisk), or insulin glulisine (sanofi-aventis), begins to work about five minutes after injection, peaks in about one hour, and continues to work for two to four hours.
• Regular or Short-acting insulin (human) usually reaches the bloodstream within 30 minutes after injection, peaks anywhere from two to three hours after injection, and is effective for approximately three to six hours.
• Intermediate-acting insulin (human) generally reaches the bloodstream about 2 to 4 hours after injection, peaks four to 12 hours later, and is effective for about 12 to 18 hours.
• Long-acting insulin (glargine or detemir) reaches the bloodstream six to ten hours after injection and is usually effective for 20 to 24 hours. There are also two long-acting insulin analogues: glargine and detemir. They both tend to lower glucose levels fairly evenly over a 24-hour period with less of a peak of action than ultralente.

The most common forms of insulin are:

• Very-fast-acting: NovoLog, Humalog, and Apidra
• Fast-acting: regular insulin (Novolin R and Humulin R)
• Intermediate-acting: NPH insulin (Novolin N or Humulin N) or Lente
         insulin (Novolin L or Humulin L)
• Very-long-acting: Lantus and Levemir

The very-long-acting insulins Lantus and Levemir have little or no "peak" in their activity. They provide a relatively steady amount of insulin action over many hours and are rarely a problem with exercise. All other insulins rise to a point of maximum or peak activity, after which their action begins to decline.

The fast and very-fast-acting insulins, which peak between one and three hours after injection and are usually taken with meals, rapidly lower blood sugar. The same dose of insulin that lowers your blood sugar to just the right level after meals could cause your sugar to dip too low during exercise, especially if you are exercising during the period of maximum blood sugar lowering action. In general, you should not exercise during the peak time periods after injecting the insulin because this is when there is the greatest likelihood of hypoglycemia.

If you are taking an intermediate-acting insulin, now you're contending with a five- to seven-hour peak. For example, let's say you're taking NPH at breakfast and at dinner, and you experience a low blood sugar reaction during afternoon exercise. That's probably because you took too much insulin in the morning. Work with your doctor on reducing that morning dose on exercise days. And while you may need to lower your evening dose right after having the hypoglycemic reaction, this should not be the way you deal with this problem in the future. It's all about preventing the hypoglycemia to begin with by hitting on the right A.M. dose.