Isophane insulins

NPH Isophane Human Insulin Suspension. NPH isophane insulin, also called Humulin N, Insulatard NPH Human, or Novolin N is an intermediate-acting form of human insulin produced by recombinant DNA techniques. Mixtures Humulin 70/30 and Novolin 70/30 contain 70% NPH isophane and 30% regular, whereas Humulin 50/50 contains 50% NPH isophane and 50% regular. It is adrninistered subcutaneously and should not be given intravenously. Absorption is delayed because the insulin is conjugated with protamine in a complex of reduced isoelectric solubiUty. Therapeutically, this preparation is probably comparable to purified porcine NPH insulin. However, human NPH insulin may have a slightly shorter duration of action than comparable purified porcine products. 

Therapeutic Function Hypoglycemic Chemical Name Isophane insulin Common Name Isophane insulin injection... 

A patient is required to take 10 units of U-40 isophane insulin suspension and 18 units of U-100 protamine zinc insulin. What volume, in milliliters, of each type will provide the desired dosage ... 

A medication order in the hospital setting calls for isophane insulin suspension to be administered to a 152-lb patient on the basis of 1 unit per kg per 24 hours. How many units of isophane insulin suspension should be administered daily ... 

ISOPHANE INSULIN SUSPENSION (NPH insulin combined with protamine and zinc) ... 

Isophane insulin preparations containing equimolar quantities of insulin and protamine in order to prolong its duration of action... 

Biphasic insulins are fixed dose combinations of a short-acting and intermediate-acting insulin in various proportions. Examples are Humulin, a biosynthetic human insulin (rDNA origin) suspension with respectively 20%, 30% and 40% regular and 80%, 70% and 60% isophane insulin and Mixtard, a biphasic biosynthetic human insulin suspension with respectively 10%, 20% and 40% soluble and 90%, 80% and 60% isophane insulin. 

Pork regular and isophane insulin (in a ratio of 30 70 RAPIMIX) 40 U/ml... 

NPH Insulin Neutral Protamine Hagedorn Insulin equivalent to isophane insulin... 

Semilente insulin is a suspension of amorphous insulin zinc. The onset is 1-3 hours after subcutaneous administration, reaches maximum effect in 5-10 hours and the effect lasts 10-16 hours. Isophane insulin (NPH Neutral solution. Protamine, Hagedorn s laboratoiy insulin) is an intermediate-acting preparation prepared with protamine. The maximum effect is reached in 4-12 hours and lasts 8-26 hours. Patients using these preparations who present for cardiac surgery are at increased risk for anaphylactic reactions to protamine. Ultralente insulin is a long-acting preparation formed with zinc rather than protamine. Zinc retards the release of insulin and these preparations have a duration of up to 36 hours. Protamine zinc insulin, which contains both protamine and zinc, has a duration of 28-36 hours. 

Isophane insulin suspension and regular insulin injection (combination) ... 

Isophane insulin is a white suspension of rod-shaped crystals approximately 30- Jm long, and free from large aggregates of crystals after being subjected to moderate agitation. It contains either 1.4-1.8% glycerol, 0.15-0.17% meta-cresol, and 0.06-0.07% phenol on a wt/vol basis, or 1.4—1.8% glycerol and 0.20-0.25% phenol (wt/vol), at a pH of 7.1-7.4. It also contains 0.15-0.25% (wt/vol) of sodium phosphate, 0.01-0.04 mg of zinc, and 0.3—0.6 mg of protamine for each USP insulin unit. The insoluble matter in the suspension is crystalline and contains not more than traces of amorphous material. 

Pramlintide buffers to a pH of 4.0 and precipitates at a pH at above 5.5 and would not be expected to be compatible with insulin, which is buffered at pH 7.8. In an open study of 51 patients with type 1 diabetes, pramlintide was mixed in the same syringe as insulin (regular insulin and isophane insulin) (10). The pharmacokinetics of insulin and pramlintide were not significantly altered. However, mixing pramlintide and insulin is not recommended. 

A 54-year-old woman with gestational diabetes was later found to be allergic to chromium, pollen, dust, penicillin, acarbose, and metformin (130). She was treated with diet and glibenclamide, but later required insulin. With Humulin N insulin she developed a wheal of 15 mm immediately after the injection, which resolved in a few hours. However, a painful itchy induration appeared 2-3 hours after the injection and lasted a few days. She had an immediate reaction to isophane insulin, with induration, but insulin lispro was well-tolerated. 

Gelified nasal insulin has been compared with twice daily isophane insulin and three times daily subcutaneous regular insulin in 16 patients with type 1 diabetes (261). Three patients had to withdraw because of nasal burning and one because of persistent sinusitis. One patient had purulent sinusitis after 6 months. The efficacy of gelified insulin was comparable to that of regular insulin. 

A 68-year-old woman with diabetes and hypertension using 42 units of isophane insulin and propranolol 20 mg qds died with a blood glucose concentration below 1.4 mmol/1 without any symptoms of hypoglycemia (290). 

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