Insulin

insulin (in' su lin) Insulin injection:

Humulin R, Humulin R Regular U-500 (concentrated), Novolin R, Novolin R PenFill, Novolin ge Toronto (CAN), Regular Iletin II, Velosulin Human BR Insulin lispro:

Humalog Isophane insulin suspension (NPH):

Humulin N, Novolin N, Novolin N PenFill, Novolin ge (CAN), NPH Ilentin II Insulin zinc suspension (Lente):

Humulin-L, Lente Ilentin II, Lente L, Novolin ge lente (CAN) Protamine zinc suspension (PZI):

Iletin PZI (CAN) Insulin zinc suspension, extended (Ultralente):

Humulin U (CAN), Humulin U Ultralente Insulin injection concentrated:

Novolin ge Ultralente (CAN), Regular (concentrated) Iletin II Insulin Aspart:

Novolog Insulin Glargine:

Lantus Combination insulins:

Humalog 75/25, Humulin 70/30, Humulin 50/50, Novolin 70/30, Novolog 70/30 Pregnancy Category B Drug classes

Antidiabetic Hormone Therapeutic actions

Insulin is a hormone secreted by the pancrease that, by receptor-mediated effects, promotes the storage of the body's fuels, facilitating the transport of metabolites and ions (potassium) through cell membranes and stimulating the synthesis of glycogen from glucose, of fats from lipids, and proteins from amino acids. Indications

• • • • •

Treatment of type 1 (insulin-dependent) diabetes Treatment of type 2 (non–insulin-dependent) diabetes that cannot be controlled by diet or oral agents Treatment of severe ketoacidosis or diabetic coma (regular insulin injection) Treatment of hyperkalemia with infusion of glucose to produce a shift of potassium into the cells Highly purified and human insulins promoted for short courses of therapy (surgery, intercurrent disease), newly diagnosed patients, patients with poor metabolic control, and patients with gestational diabetes

• • •

Insulin injection concentrated indicated for treatment of diabetic patients with marked insulin resistance (requirements of > 200 units/day) Glargine (Lantus): Treatment of adult patients with type 2 diabetes who require basal insulin control of hyperglycemia Treatment of adults and children > 6 yr who require baseline insulin control

Contraindications and cautions

• •

Contraindicated with allergy to pork products (varies with preparations; human insulin not contraindicated with pork allergy). Use cautiously with pregnancy (keep patients under close supervision; rigid control is desired; following delivery, requirements may drop for 24–72 hr, rising to normal levels during next 6 wk); lactation (monitor mother carefully; insulin requirements may decrease during lactation).

Available forms

Injection—100 units/mL, 500 units/mL (concentrated); pre-filled cartridges and pens— 100 units/mL Dosages ADULTS AND PEDIATRIC PATIENTS

General guidelines, 0.5–1 unit/kg/day. The number and size of daily doses, times of administration, and type of insulin preparation are determined after close medical scrutiny of the patient's blood and urine glucose, diet, exercise, and intercurrent infections and other stresses. Usually given SC. Regular insulin may be given IV or IM in diabetic coma or ketoacidosis. Insulin injection concentrated may be given SC or IM, but do not administer IV. • Adults with type 2 diabetes requiring basal insulin control: 10 units/day SC, given at the same time each day. Range, 2–100 units/day (Lantus only). Pharmacokinetics Type Regular Semilente NPH Lente PZI Ultralente Lispro Aspart Glargine Combination insulins

Onset 30–60 min 1–1.5 hr 1–1.5 hr 1–2.5 hr 4–8 hr 4–8 hr < 15 min 10–20 min 60 min 30–60 min, then 1–2 hr

Peak 2–3 hr 5–10 hr 4–12 hr 7–15 hr 14–24 hr 10–30 hr 30–90 min 1–3 hr None 2–4 hr, then 6–12 hr

Duration 6–8 hr 12–16 hr 24 hr 24 hr 36 hr > 36 hr 6–8 hr 3–5 hr 24 hr 6–8 hr, then 18–24 hr

Metabolism: Cellular; T1/2: Varies with preparation Distribution: Crosses placenta; does not enter breast milk IV facts

Preparation: May be mixed with standard IV solutions; use of plastic tubing or bag will change the amount of insulin delivered.

Infusion: Use of a monitored delivery system is suggested. Rate should be determined by patient response and glucose levels. Incompatibilities: Do not add to aminophylline, amobarbital, chlorothiazide, cytarabine, dobutamine, methylprednisolone, pentobarbital, phenobarbital, phenytoin, secobarbital, sodium bicarbonate, thiopental. Adverse effects

• • •

Hypersensitivity: Rash, anaphylaxis or angioedema Local: Allergy—local reactions at injection site—redness, swelling, itching; usually resolves in a few days to a few weeks; a change in type or species source of insulin may be tried; lipodystrophy; pruritus Metabolic: Hypoglycemia; ketoacidosis

Interactions

Drug-drug • Increased hypoglycemic effects of insulin with MAOIs, beta blockers, salicylates, or alcohol • Delayed recovery from hypoglycemic episodes and masked signs and symptoms of hypoglycemia if taken with beta-adrenergic blocking agents Drug-alternative therapy • Increased risk of hypoglycemia if taken with juniper berries, ginseng, garlic, fenugreek, coriander, dandelion root, celery Nursing considerations CLINICAL ALERT!

Name confusion may occur between Lantus and Lente insulin; use extreme caution. Assessment

• •

History: Allergy to pork products; pregnancy; lactation Physical: Skin color, lesions; eyeball turgor; orientation, reflexes, peripheral sensation; P, BP, adventitious sounds; R, adventitious sounds; urinalysis, blood glucose

Interventions

• • • •

Ensure uniform dispersion of insulin suspensions by rolling the vial gently between hands; avoid vigorous shaking. Give maintenance doses SC, rotating injection sites regularly to decrease incidence of lipodystrophy; give regular insulin IV or IM in severe ketoacidosis or diabetic coma. Monitor patients receiving insulin IV carefully; plastic IV infusion sets have been reported to remove 20%–80% of the insulin; dosage delivered to the patient will vary. Do not give insulin injection concentrated IV; severe anaphylactic reactions can occur.

•

• •

•

• • •

Use caution when mixing two types of insulin; always draw the regular insulin into the syringe first; if mixing with insulin lispro, draw the lispro first; use mixtures of regular and NPH or regular and Lente insulins within 5–15 min of combining them; Lantus insulin (insulin glargine) cannot be mixed in solution with any other drug, including other insulins. Double-check, or have a colleague check, the dosage drawn up for pediatric patients, for patients receiving concentrated insulin injection, or patients receiving very small doses; even small errors in dosage can cause serious problems. Carefully monitor patients being switched from one type of insulin to another carefully; dosage adjustments are often needed. Human insulins often require smaller doses than beef or pork insulin; monitor cautiously if patients are switched; lispro insulin is given 15 min before a meal. Store insulin in a cool place away from direct sunlight. Refrigeration is preferred. Do not freeze insulin. Insulin prefilled in glass or plastic syringes is stable for 1 wk refrigerated; this is a safe way of ensuring proper dosage for patients with limited vision or who have problems with drawing up insulin. Monitor urine or serum glucose levels frequently to determine effectiveness of drug and dosage. Patients can learn to adjust insulin dosage on a sliding scale based on test results. Monitor insulin needs during times of trauma or severe stress; dosage adjustments may be needed. Keep life support equipment and glucose readily available to deal with ketoacidosis or hypoglycemic reactions.

Teaching points

• • • • • • • • •

Use the same type and brand of syringe; use the same type and brand of insulin to avoid dosage errors. Do not change the order of mixing insulins. Rotate injection sites regularly (keep a chart) to prevent breakdown at injection sites. Dosage may vary with activities, stress, diet. Monitor blood or urine glucose levels, and consult physician if problems arise. Store drug in the refrigerator or in a cool place out of direct sunlight; do not freeze insulin. If refrigeration isn't possible, drug is stable at controlled room temperature less than 30° C (86° F) and out of direct sunlight for up to 28 days; do not freeze insulin. Monitor your urine or blood for glucose and ketones as prescribed. Wear a medical alert tag stating that you are a diabetic taking insulin so that emergency medical personnel will take proper care of you. Avoid alcohol; serious reactions can occur. Report fever, sore throat, vomiting, hypoglycemic or hyperglycemic reactions, rash.

Adverse effects in Italic are most common; those in Bold are life-threatening.