Drug Name
Generic Name : insulin
Brand Name:
- Inhaled insulin: Exubera
- Insulin injection: Humulin R, Humulin R Regular U-500 (concentrated), Novolin ge Toronto (CAN), Novolin R, Novolin R PenFill
- Insulin injection concentrate: Humulin R Regular U-500
- Insulin lispro: Humalog
- Isophane insulin suspension (NPH): Humulin N, Novolinge (CAN), Novolin N, Novolin N PenFill, Novolin ge NPH (CAN)
- Insulin zinc suspension (Lente): Humulin-L, Lente Ilentin II, Novolinge lente (CAN)
- Protamine zinc suspension (PZI): Iletin PZI (CAN)
- Insulin zinc suspension, extended (Ultralente): Humulin U
- Insulin Aspart: NovoLog
- Insulin Detemir: Levemir
- Insulin Glargine: Lantus
- Insulin Glulisine: Apidra
- Combination insulins: Humalog 75/25; Humulin 70/30; Humulin 50/50; Novolin 70/30; Novolinge 10/90, 20/80, 30/70, 40/60, 50/50 (CAN)
Classification: Antidiabetic, Hormone
Pregnancy Category B
Pregnancy Category C (exubera, insulin glargine, insulin aspart, insulin glulisine)
Dosage & Route
ADULTS
- 1–6 mg inhaled insulin (Exubera) based on weight, 10 min before a meal. Adjust dosage based on patient response
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 subcutaneously. Regular insulin may be given IV or IM in diabetic coma or ketoacidosis. Insulin injection concentrated may be given subcutaneously or IM but do not administer IV.
ADULTS WITH TYPE 2 DIABETES REQUIRING BASAL INSULIN CONTROL
- 10 units/day subcutaneously, given at the same time each day. Range, 2–100 units/day (Lantus) or 0.1–0.2 units/kg subcutaneously in the evening or 10 units once or twice a day (Levemir).
Therapeutic actions
- Insulin lowers blood glucose levels. It regulates carbohydrate, protein and fat metabolism by inhibiting hepatic glucose production and lipolysis, and enhancing peripheral glucose disposal. The various insulin formulations are classified according to their durations of action after SC Inj. They are divided into short-, intermediate-, or long-acting insulin. Soluble insulin (also known as ‘neutral insulin’ or ‘regular insulin’) is a short-acting preparation. To extend the duration of action of insulin, preparations are formulated as suspensions in 2 methods. The 1st method involves complexing insulin with a protein so that it is slowly released, e.g. protamine zinc insulin (contains an excess of protamine) and isophane insulin (or NPH insulin which contains equal amounts of protamine and insulin). An alternative method is particle size modification e.g. insulin zinc suspensions. While all the formulations can be admin by SC inj, most by IM inj, only soluble insulin can be admin by IV. Compared to SC inj, IM admin usually has a faster onset of action, with a shorter duration of action.
- Onset: 0.5-1 hr (short-acting e.g. soluble insulin); 2 hr (intermediate-acting e.g. biphasic insulin, isophane insulin, amorphous insulin zinc suspensions); 2-3 hr (mixed-insulin Zn suspension); 4 hr (long-acting e.g. insulin zinc suspensions, protamine zinc insulins).
- Duration: 6-8 hr (short-acting e.g. soluble insulin); 24 hr (intermediate-acting e.g. biphasic insulin, isophane insulin, amorphous insulin zinc suspensions); 30 hr (mixed-insulin Zn suspension); 36 hr (long-acting e.g. insulin zinc suspensions, protamine zinc insulins).
- Absorption: Inactivated (oral); fairly rapid (SC); rapid (IM); increased by exercise.
- Metabolism: Mainly in liver, also in kidneys and muscle tissue.
- Excretion: Small amount excreted as unchanged drug in urine.
Indications
- Treatment of type 1 diabetes mellitus
- Treatment of type 2 diabetes mellitus that cannot be controlled by diet or oral drugs
- Regular insulin injection: Treatment of severe ketoacidosis or diabetic coma
- 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: Treatment of diabetic patients with marked insulin resistance (requirements of > 200 units/day)
- Glargine (Lantus): Treatment of adult patients with type 2 diabetes mellitus who require basal insulin control of hyperglycemia
- Treatment of adults and children > 6 yr who require baseline insulin control
- Determir (Levemir): Treatment of adults with diabetes who require basal insulin for the control of hyperglycemia
Adverse effects
- Hypoglycemia, insulin resistance, lipoatrophy, hypokalaemia, blurred vision.
Contraindications
- Hypoglycemia.
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; urinalysis, blood glucose
Interventions
- Ensure uniform dispersion of insulin suspensions by rolling the vial gently between hands; avoid vigorous shaking.
- Give maintenance doses subcutaneously, rotating injection sites regularly to decrease incidence of lipodystrophy; give regular insulin IV or IM in severe ketoacidosis or diabetic coma.
- Obtain baseline and periodic PFTs for patient using inhaled insulin; carefully monitor glucose levels when converting from subcutaneous to inhaled insulin
- 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) and Levemir (insulin detemir) cannot be mixed in solution with any other drug, including other insulins.
- WARNING: 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; 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. Levemir is given in the evening.
- 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.
- WARNING: 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. Arrange for proper disposal of syringes.
- Do not change the order of mixing insulins. Rotate injection sites regularly (keep a chart of sites used) to prevent breakdown at injection sites.
- Review the use, storage, and cleaning of the insulin inhaler with your health care provider. Periodic tests of lung function will be needed. Close glucose monitoring will be needed as you switch from other forms of insulin.
- Dosage may vary with activities, stress, diet. Monitor blood or urine glucose levels, and consult health care provider if problems arise.
- Store drug in the refrigerator or in a cool place out of direct sunlight; do not freeze insulin.
- If refrigeration is not possible, drug is stable at controlled room temperature and out of direct sunlight for up to 1 month.
- Monitor your urine or blood levels for glucose and ketones as prescribed.
- Wear a medical alert tag stating that you have diabetes and are 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.