Regular insulin and NPH insulin have been on the market for many years. Regular insulin is also referred to as a short-acting insulin, while NPH is sometimes called an intermediate-acting insulin.
These older insulins are less expensive than newer insulins, but they can be difficult to match to the body’s insulin needs. Regular insulin usually needs to be given at least 15–30 min before eating. These medications tend to be more variable in the body (meaning the effect of any given dose is less easy to predict) and can cause more low blood glucose reactions. NPH insulin has a peak of activity somewhere from 6 to 12 hours after it is injected, so it is not a good long-acting insulin.
If you work with a diabetes team familiar with their use, it is possible to manage type 1 diabetes with these older, much less expensive insulins. Newer insulins are preferred for the treatment of type 1 diabetes, if possible.
Newer insulins have some advantages, such as being more reliable and predictable in terms of how they act and causing fewer low blood glucose reactions.
Rapid-Acting (Lispro, Aspart, Glulisine) and Ultra-Rapid-Acting Insulin (fiasp)
Rapid-acting insulins are made for fast absorption so they manage the postmeal peak glucose level. These insulin types are broken down fairly quickly in the body, lowering the risk of hypoglycemia in the hours after a meal.
They are usually given either immediately before a meal or 10–20 minutes in advance, depending on the blood glucose level. Sometimes people give ~50% of the dose before the meal and then give the appropriate remainder when the meal is finished. This strategy can be helpful with small children and seniors who are having challenges eating.
These are the insulins that are used in insulin pumps.
In premixed insulins, part of the insulin is long-acting and part is short- or rapid-acting. Premixed insulins are generally not preferred because the ratios of shorter- to longer-acting insulin are fixed—you can’t give more short-acting insulin because the blood glucose is higher or more carbohydrates will be eaten. But for some people, in some settings, these insulins are helpful. It all comes back to the team and what works best for you/your child.
Afrezza rapid-acting insulin is a powder that is absorbed through the lungs. It works even more rapidly than rapid-acting insulin and also stops working more quickly. It must be used along with a long-acting insulin in people with type 1 diabetes. Smokers and those with asthma or other lung problems should not use inhaled insulin. Afrezza is not yet approved for children; however, studies are underway. The smallest amount that can be delivered in an inhaler is too much for most children.