Ppt chapter 49

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Chapter 49

Drugs Affecting Blood Glucose Levels

Chapter 49

Drugs Affecting Blood Glucose Levels


QuestionQuestion

• What percentage of the population has diabetes mellitus?

– A. 3.4%

– B. 7.8%

– C. 14.2%

– D. 21.7%


AnswerAnswer

• B. 7.8%

• Rationale: Diabetes mellitus is a common chronic disease that affects 23.6 million people in the United States, or 7.8% of the population (Centers for Disease Control and Prevention [CDC], 2010a).


Diabetes Mellitus Diabetes Mellitus

• Although an estimated 23.6 million people are diagnosed with diabetes, 5.7 million are unaware they have the disease.

• Approximately 5% to 10% of Americans diagnosed with diabetes have type 1, whereas 90% to 95% have type 2.

• People with diabetes are at increased risk for cardiovascular disease, kidney failure, blindness, nervous system disease, extremity amputations, dental disease, and complications of pregnancy.


Diabetes Mellitus (cont.)Diabetes Mellitus (cont.)

• In 2007, the total annual economic cost of diabetes was estimated to be $174 billion.

• Exogenous insulins are used to replace deficient intrinsic insulins.

• Oral antidiabetic drugs are used to control type 2 diabetes, in which there is insulin resistance.


Physiology Physiology

• Glucose is made available to the body from food that is ingested and from the production of glucose by the liver.

• Unable to store or synthesize glucose, the brain depends on a steady supply of glucose from the circulation and extracts its energy on a nearly continuous basis.

• Three body systems are involved in the regulation and use of glucose—the liver, pancreas, and skeletal muscle tissue.

• The liver synthesizes its own glucose supply (a process called gluconeogenesis) in addition to storing and releasing glucose.

• The pancreas is both an exocrine and an endocrine gland.

• Insulin regulates carbohydrate metabolism.


Pathophysiology Pathophysiology

• Diabetes mellitus is a serious chronic disease that affects people of all ages and ethnic groups.

• Type 1 diabetes is an autoimmune disorder characterized by the destruction of the insulin-secreting beta cells in the pancreas, leading to absolute insulin deficiency.

• Type 2 diabetes is the result of insulin resistance by the tissues and usually a decrease in insulin production.

• Gestational diabetes mellitus (GDM) occurs when a woman’s pancreatic function is not sufficient to overcome the insulin resistance created by the anti-insulin hormones secreted by the placenta.


Type 1 Diabetes MellitusType 1 Diabetes Mellitus


Type 2 Diabetes Mellitus Type 2 Diabetes Mellitus


Insulins Insulins

• Synthetic insulin (exogenous) acts in the same manner as endogenously produced insulin.

• Sources of exogenous insulin historically included pork and beef pancreas, but now only recombinant DNA technology or genetic engineering is used to create human-like insulin.

• Modifying the amino acid sequence of the human insulin molecule has resulted in new, rapid-acting insulin analogues, such as aspart, lispro, or glulisine (produced by rDNA technology).

• Human-sourced insulin is considered the standard therapy.

• The potency of insulin is expressed in United States Pharmacopeia (USP) or international units.


Regular Insulin: Core Drug Knowledge Regular Insulin: Core Drug Knowledge

• Pharmacotherapeutics

– All types of diabetes mellitus

• Pharmacokinetics

– Administered: SC or IV

• Pharmacodynamics

– Injected insulin mimics the effect of endogenous insulin


Regular Insulin: Core Drug Knowledge (cont.)Regular Insulin: Core Drug Knowledge (cont.)

• Contraindications and precautions

– Hypoglycemia

• Adverse effects

– Hypoglycemia and lipoatrophy

• Drug interactions

– Alcohol, beta-blockers, dobutamine, niacin, MAOIs, thiazide diuretics, and tetracycline


Regular Insulin: Core Patient Variables Regular Insulin: Core Patient Variables

• Health status

– Assess medical status.

• Life span and gender

– Assess pregnancy status.

• Lifestyle, diet, and habits

– Assess impact of diabetes on lifestyle.

• Environment

– Assess the environment where the drug will be given.


Regular Insulin: Nursing Diagnoses and Outcomes Regular Insulin: Nursing Diagnoses and Outcomes

• Deficient Knowledge related to insulin pharmacotherapeutics

– Desired outcome: The patient (or family) will state brand, type, onset, peak, duration, and dose of insulin.

• Risk for Nonadherence to Self-Care related to the complexity and chronic nature of the insulin regimen.

– Desired outcome: The patient will adhere to the treatment regimen and communicate an understanding of the insulin regimen.


Regular Insulin: Nursing Diagnoses and Outcomes (cont.)Regular Insulin: Nursing Diagnoses and Outcomes (cont.)• Potential Complication: Hypoglycemia related to

administration of too much insulin.

– Desired outcome: The patient will assess for and report signs and symptoms of hypoglycemia and if an episode should occur will implement the appropriate treatment.

• Pain related to insulin injections and self-monitoring blood glucose testing via fingerstick

– Desired outcome: The patient will state two nonpharmacologic methods used to control pain and will demonstrate proper SC injection and fingerstick techniques to minimize pain.


Regular Insulin: Planning and InterventionsRegular Insulin: Planning and Interventions

• Maximizing therapeutic effects

– Store opened vials of regular insulin at room temperature.

– Administer regular insulin with an insulin syringe into an appropriate subcutaneous site.

• Minimizing adverse effects

– Injection-site rotation also helps prevent lipodystrophy.

– Assess blood glucose level prior to administration.


Regular Insulin: Teaching, Assessment, and EvaluationRegular Insulin: Teaching, Assessment, and Evaluation

• Patient and family education

– Discuss how to administer insulin properly.

– Discuss storage of insulin.

– Discuss side effects of therapy.

• Ongoing assessment and evaluation

– Evaluate ability to administer insulin.

– Monitor fasting blood glucose and hemoglobin A1C levels.


QuestionQuestion

• Which of the following SC site provides the most rapid absorption of insulin therapy?

– A. Arm

– B. Abdomen

– C. Buttocks

– D. Thigh


AnswerAnswer

• B. Abdomen

• Rationale: The most rapid absorption occurs when administration is into the abdominal SC layer (as much as 50% faster than other routes).

• The next most rapid is into the arm, followed by the thigh, and finally the buttocks.


Rapid-Acting Insulins Rapid-Acting Insulins

• Three rapid-acting insulins that are analogues of rapid-acting regular insulin are now available: aspart (NovoLog), lispro (Humalog), and glulisine (Apidra).

• Administer within 15 minutes of start of the meal.

• Can be used in insulin pumps


Long-Acting InsulinLong-Acting Insulin

• NPH

– Onset: 1 to 1.5 hours. Peak: 4 to 12 hours. Duration: up to 24 hours.

• Glargine

– Duration: 24 hours. No peak.

• Exubera

– Onset: 10 to 20 minutes.

– Inhaled insulin


Insulin TherapyInsulin Therapy


Noninsulin Antidiabetic Medications Noninsulin Antidiabetic Medications

• Until the mid-1990s, the sulfonylurea drugs were the only class of oral antidiabetic agents available to manage type 2 diabetes.

• Currently, five chemical classes of oral antidiabetic agents are available.

• Sulfonylureas

– Prototype drug: glyburide (DiaBeta)


Glyburide: Core Drug Knowledge Glyburide: Core Drug Knowledge


– Adjunctive treatment to lower blood glucose levels in diabetes mellitus type 2


– Administered: oral. Metabolism: liver. Excreted: urine and feces. Onset: 2 hours. Protein bound.


– Hypoglycemic action of glyburide results from the stimulation of pancreatic beta cells.


Glyburide: Core Drug Knowledge (cont.)Glyburide: Core Drug Knowledge (cont.)


– Hypersensitivity

• Adverse effects

– Hypoglycemia, anorexia, nausea, vomiting, heartburn, and a metallic taste in the mouth


– Drug interactions are possible because these drugs are metabolized by the CYP3A3/4 system.


Glyburide: Core Patient Variables Glyburide: Core Patient Variables

• Health status

– Assess overall health before starting therapy.


– Pregnancy Category B drug


– Assess willingness to follow diet.

• Environment



Glyburide: Nursing Diagnoses and Outcomes Glyburide: Nursing Diagnoses and Outcomes • Ineffective Health Maintenance related to glyburide-

induced nausea, vomiting, abdominal pain, and disulfiram-like reaction secondary to alcohol ingestion

– Desired outcome: The patient will follow American Diabetes Association dietary guidelines and avoid consuming alcohol.

• Imbalanced Nutrition: More than Body Requirements related to weight gain secondary to glyburide/sulfonylurea therapy

– Desired outcome: The patient will follow American Diabetes Association dietary guidelines and not experience a weight gain.


Glyburide: Nursing Diagnoses and Outcomes (cont.)Glyburide: Nursing Diagnoses and Outcomes (cont.)

• Ineffective Protection related to leukopenia secondary to bone marrow depression associated with glyburide use

– Desired outcome: The patient will be free from infection while taking glyburide.


Glyburide: Planning and InterventionsGlyburide: Planning and Interventions


– Administer glyburide before breakfast or the first main meal of the day.


– Monitor the patient’s blood glucose levels periodically throughout therapy to detect hypoglycemia.

– Monitor patients with renal and hepatic impairment for signs of adverse effects.


Glyburide: Teaching, Assessment, and EvaluationGlyburide: Teaching, Assessment, and Evaluation


– Teach about diabetes management.

– Teach patients and families the signs and symptoms of hypoglycemia.


– Interview the patient and family and observe for therapeutic and adverse responses to glyburide and adherence to prescribed treatments.


QuestionQuestion

• The mechanism of action of glyburide is the decreased production of insulin by the liver, which results in decreased blood glucose levels.

– A. True

– B. False


AnswerAnswer

• B. False

• Rationale: The mechanism of action of glyburide is stimulation of the beta cells in the pancreas. Hypoglycemic action of glyburide results from the stimulation of pancreatic beta cells.


Nonsulfonylureas Nonsulfonylureas

• The nonsulfonylurea antidiabetics comprise three different classes grouped by their chemical structure: biguanides, thiazolidinediones, and alpha-glucosidase inhibitors.

• These drugs are considered by their mode of action:

– Improving insulin action

– Delaying the digestion of carbohydrates

• Prototype drug: metformin (Fortamet, Glucophage)


Metformin: Core Drug Knowledge Metformin: Core Drug Knowledge


– Adjunct to therapy to lower blood glucose in type 2 diabetes


– Administered: oral. Metabolism: liver. Excreted: kidneys.


– Decreases hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake.


Metformin: Core Drug Knowledge (cont.)Metformin: Core Drug Knowledge (cont.)


– Hepatic disease

• Adverse effects

– Anorexia, nausea and vomiting, weight loss, abdominal discomfort, dyspepsia, flatulence, diarrhea, and a metallic taste sensation


– May react with contrast media used for radiographic procedures


Metformin: Core Patient Variables Metformin: Core Patient Variables

• Health status

– Assess medical history and current medical status.




– Assess diet, exercise, and alcohol intake.

• Environment


• Culture and inherited traits

– The drug has been studied in several ethnic groups.


Metformin: Nursing Diagnoses and Outcomes Metformin: Nursing Diagnoses and Outcomes

• Risk for Imbalanced Nutrition: Less than Body Requirements related to anorexia secondary to adverse GI effects of weight loss, diarrhea, and anorexia from metformin

– Desired outcome: The patient will ingest daily nutritional requirements in accordance with activity level and metabolic needs and relate the importance of good nutrition.


Metformin: Planning and InterventionsMetformin: Planning and Interventions


– Administer metformin twice a day with the morning and evening meal.

– Adherence with the recommended diabetic diet and daily exercise help in the control of type 2 diabetes.


– Taking the drug at mealtimes and using gradual dosage increments minimize these effects.


Metformin: Teaching, Assessment, and EvaluationMetformin: Teaching, Assessment, and Evaluation


– Teach patients to take metformin with meals, morning and evening.

– Emphasize that patients should not use alcohol while taking metformin.


– Monitor blood glucose levels (fasting and hemoglobin A1C) throughout metformin therapy.


QuestionQuestion

• Metformin is contraindicated in which patients?

– A. Type 2 diabetics with open skin lesion

– B. Type 2 diabetics with chronic obstructive pulmonary disease

– C. Type 2 diabetics with coronary artery disease

– D. Type 2 diabetics with cirrhosis


AnswerAnswer

• D. Type 2 diabetics with cirrhosis

• Rationale: Metformin is contraindicated in patients with chronic liver disease.


Glucose-Elevating Agents Glucose-Elevating Agents

• Glucagon is a hyperglycemic polypeptide hormone produced by the alpha cells of the pancreatic islets of Langerhans.

• Its physiologic effect is generally the opposite of that of insulin.

• Glucagon is the body’s first line of defense against hypoglycemia.

• The main stimulus to glucagon secretion is a decrease in intracellular glucose concentrations that usually occurs as a result of a drop in serum blood sugar.

• Glucagon (GlucaGen) is used in unconscious patients to reverse insulin overdose.


Glucagon: Core Drug Knowledge Glucagon: Core Drug Knowledge


– Hypoglycemia


– T½: 3 to 10 minutes


– Increases blood glucose levels by stimulating glycogenolysis in the peripheral tissues


Glucagon: Core Drug Knowledge (cont.)Glucagon: Core Drug Knowledge (cont.)


– Hypersensitivity

• Adverse effects

– Hypotension, respiratory distress, nausea and vomiting


– Oral anticoagulants


Glucagon: Core Patient Variables Glucagon: Core Patient Variables

• Health status

– Assess blood glucose level and level of consciousness.




– Review adherence to treatment plan.

• Environment



Glucagon: Nursing Diagnoses and Outcomes Glucagon: Nursing Diagnoses and Outcomes

• Risk for Injury related to hypotension from the adverse effects of glucagon

– Desired outcome: Substantial hypotension will not result from glucagon treatment.


Glucagon: Planning and InterventionsGlucagon: Planning and Interventions


– Use reconstituted glucagon immediately.

– A dose of 0.5 to 1.0 mg is usually effective.


– Administer supplemental carbohydrates as soon as possible once consciousness has been achieved.


Glucagon: Teaching, Assessment, and EvaluationGlucagon: Teaching, Assessment, and Evaluation


– Emphasize to patients and family members measures to prevent hypoglycemic reactions from insulin.

– Instruct family members in the proper technique for emergency administration of glucagon.


– Blood glucose levels should be monitored before, during, and after glucagon administration.


QuestionQuestion

• The usual dose of glucagon is

– A. 0.5 to 1 mg

– B. 2.5 to 5 mg

– C. 7.5 to 10 mg

– D. 12.5 to 15 mg


Answer Answer

• A. 0.5 to 1 mg

• Rationale: The usual dose of glucagon is 0.5 to 1.0 mg.

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