Although undergoing some major improvements over the past several years, human insulin still has some limitations. The human insulins have variable and inconsistent absorption rates that cause erratic and unpredictable blood-glucose-lowering effects, resulting from the varying onset of actions, peak, and duration of action of these products. This is because when regular insulin is administered subcutaneously, its absorption into the circulation is slow, with a subsequent slow onset of action. Therefore, regular insulin should be administered 30-40 minutes before a meal to avoid a potential physiological mismatch, with subsequent hypoglycemia.
This advance administration can become inconvenient or somewhat hazardous at times, particularly if the patient is unable to eat and has taken insulin (e.g., if the meal becomes surprisingly delayed or is not palatable to the patient). Additionally, when larger doses of regular insulin are given subcutaneously, the duration of action is prolonged, which may result in an increased risk of hypoglycemia.
Intermediate human insulins, such as NPH and Lente, are usually used in daily once-a-day, twice-a-day, or at-bedtime regimens. Intermediate human insulins usually have a gradual onset of action and a pronounced effect, usually 4-8 hours after injection. Again, the problem is that these agents demonstrate significant variations both within each patient and from patient to patient. Administration of intermediate human insulins still requires a strict schedule for meal intake to take advantage of their onsets of action (16).
Because of the prolonged effects of intermediate human insulins, postprandial hypo-glycemia and overlapping of peak effects may occur, contributing to recurrent episodes of hypoglycemia and Somogyi phenomena. The Somogyi phenomena can be demonstrated in individuals who exhibit weight gain with less than 5% glucose spillage in their urine in the face of elevated glucoses. In this setting, the patient should be treated with a reduction of insulin for better control and less hypoglycemia.
Ultralente has a long duration of action (16-20 hours) but unfortunately, once again, demonstrates substantial day-to-day variability, with broad and erratic peaks, which makes its use more difficult.
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Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...