Synthetic human insulin is identical in structure to your own natural insulin. But when it is injected under the skin it doesn’t work as well as natural insulin. This is because injected human insulin clumps together and takes a long time to get absorbed. The activity of this synthetic human insulin is not well synchronized with your body’s needs.
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Relative to the rapid-acting insulin analogs, Regular human insulin has undesirable features, such as a delayed onset of action, and variable peak and duration of action when it is injected under the skin. Because of this, fewer and fewer medical providers are prescribing Regular insulin. The delayed onset of action is the reason you have to inject the insulin and wait before eating. And the variable duration of action predisposes to low blood sugars long after the meal is over.
REGULAR INSULIN IS LESS PREDICTABLE THAN RAPID-ACTING ANALOG VERSIONS when injected under the skin.
NPH (Neutral Protamine Hagedorn) is a longer-acting human insulin that is used to cover blood sugar between meals, and to satisfy your overnight insulin requirement. A fish protein, protamine, has been added to the Regular human insulin to delay its absorption. This long acting insulin is a cloudy suspension that needs to be remixed thoroughly before each injection. Because NPH is a suspension of different sized crystals, it has a very unpredictable absorption rate and action. This results in more frequent low and high blood sugars. The use of NPH has declined with the availability of other long-acting insulin options, specifically, the long-acting insulin analogs, insulin glargine and insulin detemir.
Additional information about NPH:
- An optimal NPH regimen involves small doses before meals (for between-meal insulin coverage), with a larger dose at bedtime (to cover this longer time period). In this regimen, rapid acting insulin analogs need to be given at mealtime or for high sugar correction (ie as bolus therapy).
- The traditional NPH insulin regimens use two injections of NPH per day. The first dose covers the day and the second dose covers the evening and night. With this basic regimen, Regular insulin also is given before breakfast and dinner.
- An alternative NPH regimen is to give Regular insulin alone at meals and NPH at bedtime.
- Other regimens use various combinations of rapid-acting analog insulin or Regular insulin and NPH.
USING NPH MAY RESULT IN MORE HIGH AND LOW BLOOD SUGAR LEVELS.
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