Final answer:
Insulin isophane NPH is an intermediate-acting insulin with an onset of 1 to 2 hours, a peak effect between 4 to 12 hours, and a duration of action lasting up to 18 to 24 hours. The timings of onset, peak, and duration can vary based on individual factors and are critical for effective diabetes management.
Step-by-step explanation:
Insulin Isophane NPH: Action, Onset, Peak, and Duration:
Insulin isophane NPH, commonly known as NPH insulin, is an intermediate-acting insulin used to manage blood glucose levels in people with diabetes. With a molecular weight of 5734 Da, insulin is a polypeptide composed of two chains: chain 'A' with 21 amino acids and chain 'B' with 30 amino acids. Insulin is synthesized as preproinsulin, then converted to proinsulin and finally, the active form is created by the cleavage of the 'C' chain. The action of insulin isophane NPH starts as it helps in the transport of glucose and other substances through the cell membrane.
After subcutaneous injection, the onset of action ranges around 1 to 2 hours. Its peak effect occurs typically between 4 to 12 hours during which the decline in blood glucose levels is most prominent. The action duration of NPH insulin can last up to 18 to 24 hours. However these times can vary depending on the individual's metabolism, insulin dose, injection site, and activity level. Knowing the onset, peak and duration is crucial for timing insulin injections in relation to meals and physical activities to manage glucose levels effectively.