Chapter 32 Antidiabetic Drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Chapter 32

Antidiabetic Drugs

Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Diabetes mellitus (DM) actually is not a single disease, but a group of progressive diseases. It is often regarded as a syndrome rather than a disease.

Two types Type 1 Type 2

Diabetes Mellitus

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 2

Signs and symptoms Elevated fasting blood glucose (higher than 126 mg/dL)

or a hemoglobin A1C (A1C) level greater than or equal to 6.5%

Polyuria Polydipsia Polyphagia Glycosuria Unexplained weight loss Fatigue Blurred vision

Diabetes Mellitus (cont’d)


Lack of insulin production or production of defective insulin

Affected patients need exogenous insulin Fewer than 10% of all diabetes cases are type 1 Complications

Diabetic ketoacidosis (DKA) Hyperosmolar nonketotic syndrome

Type 1 Diabetes Mellitus



Type 2 Diabetes Mellitus

Most common type: 90% of all cases Caused by insulin deficiency and insulin

resistance Many tissues are resistant to insulin

Reduced number of insulin receptors Insulin receptors less responsive


Several comorbid conditions Obesity Coronary heart disease Dyslipidemia Hypertension Microalbuminemia (protein in the urine) Increased risk for thrombotic (blood clotting) events

These comorbidities are collectively referred to as metabolic syndrome or insulin-resistance syndrome or syndrome X

Type 2 Diabetes Mellitus (cont’d)


Hyperglycemia that develops during pregnancy Insulin must be given to prevent birth defects Usually subsides after delivery 30% of patients may develop Type 2 DM within

10 to 15 years

Gestational Diabetes


Classroom Response QuestionA woman who has type II diabetes is now pregnant. She wants to know whether to take her oral antidiabetic medication. What instructions will she receive?

A.She should continue the antidiabetic medication at the same dosage.

B.The antidiabetic medication dosage will be increased gradually throughout her pregnancy.

C.She will be switched to insulin therapy while she is pregnant.

D.She will not receive any antidiabetic medication while pregnant and will need to monitor her dietary intake closely.


Macrovascular (atherosclerotic plaque) Coronary arteries Cerebral arteries Peripheral vessels

Microvascular (capillary damage) Retinopathy Neuropathy Nephropathy

Major Long-Term Complications of DM (Both Types)


Prediabetes Categories of increased risk for diabetes

• Hemoglobin A1C of 5.7% to 6.4%

• Fasting plasma glucose (FPG) levels higher than or equal to 100 mg/dL but less than 126 mg/dL

• Impaired glucose tolerance test (oral glucose challenge)

Screening recommended every 3 years for all patients 45 years and older

Screening for DM


Type 1 Insulin therapy

Type 2 Lifestyle changes Oral drug therapy Insulin when the above no longer provide glycemic

control

Treatment for DM


Insulins Oral hypoglycemic drugs

Both aim to produce normal blood glucose states Some new injectable hypoglycemic drugs may

be used in addition to insulin or antidiabetic drugs

Types of Antidiabetic Drugs


Function as a substitute for the endogenous hormone

Effects are the same as normal endogenous insulin

Restores the diabetic patient’s ability to: Metabolize carbohydrates, fats, and proteins Store glucose in the liver Convert glycogen to fat stores

Insulins


Human insulin Derived using recombinant DNA technologies Recombinant insulin produced by bacteria and yeast

Goal: tight glucose control To reduce the incidence of long-term complications

Insulins (cont’d)


Rapid-acting Most rapid onset of action (5 to 15 minutes) Shorter duration Patient must eat a meal after injection Insulin lispro (Humalog)

• Similar action to endogenous insulin

Insulin aspart (NovoLog) Insulin glulisine (Apidra) May be given subcutaneously or via continuous

subcutaneous infusion pump (but not IV)

Insulins (cont’d)


Short-acting Regular insulin (Humulin R) Onset 30 to 60 minutes

• The only insulin product that can be given by IV bolus, IV infusion, or even IM

Insulins (cont’d)


Intermediate-acting Insulin isophane suspension (also called NPH)

• Cloudy appearance

• Slower in onset and more prolonged in duration than endogenous insulin

Insulins (cont’d)


Long-acting glargine (Lantus), detemir (Levemir)

• Clear, colorless solution

• Usually dosed once daily

• Referred to as basal insulin

Insulins (cont’d)



Classroom Response Question

The nurse has just administered the morning dose of a patient’s lispro (Humalog) insulin. Just after the injection, the dietary department calls to inform the patient care unit that breakfast trays will be 45 minutes late. What will the nurse do next?A.Inform the patient of the delay.

B.Check the patient’s blood glucose levels.

C.Call the dietary department to send a tray immediately.

D.Give the patient food, such as cereal and skim milk, and juice.


Fixed combinations Humulin 70/30 Humulin 50/50 Novolin 70/30 Humalog Mix 75/25 Humalog 50/50 NovoLog 70/30

Insulins (cont’d)


Insulin use in special populations Pediatrics Pregnant women

Insulins (cont’d)


Subcutaneous short-acting or regular insulin doses adjusted according to blood glucose test results

Typically used in hospitalized diabetic patients or those on total parenteral nutrition (TPN) or enteral tube feedings

Subcutaneous insulin is ordered in an amount that increases as the blood glucose increases

Disadvantage: delays insulin administration until hyperglycemia occurs; results in large swings in glucose control

Sliding-Scale Insulin Dosing


Preferred method of treatment for hospitalized diabetic patients

Mimics a healthy pancreas by delivering basal insulin constantly as a basal and then as needed as a bolus

Basal insulin is a long-acting insulin (insulin glargine)

Bolus insulin (insulin lispro or insulin aspart)

Basal-Bolus Insulin Dosing


Used for type 2 diabetes Treatment for type 2 diabetes includes lifestyle

modifications Diet, exercise, smoking cessation, weight loss

Oral antidiabetic drugs may not be effective unless the patient also makes behavioral or lifestyle changes

Oral Antidiabetic Drugs


Biguanides metformin (Glucophage)

Sulfonylureas Second generation: glimepiride (Amaryl), glipizide

(Glucotrol), glyburide (DiaBeta, Micronase)

Oral Antidiabetic Drugs (cont’d)


Glinides repaglinide (Prandin), nateglinide (Starlix)

Thiazolidinediones pioglitazone (Actos) rosiglitazone (Avandia)

• Only available through specialized manufacturer programs

Also known as glitazones Alpha-glucosidase inhibitors

acarbose (Precose), miglitol (Glyset)



Dipeptidyl peptidase-IV (DPP-IV) inhibitors sitagliptin (Januvia) saxagliptin (Onglyza) linagliptin (Tradjenta)



Biguanides Decrease production of glucose by the liver Decrease intestinal absorption of glucose Increase uptake of glucose by tissues Do not increase insulin secretion from the pancreas

(does not cause hypoglycemia)

Oral Antidiabetic Drugs:Mechanism of Action


Sulfonylureas Stimulate insulin secretion from the beta cells of the

pancreas, thus increasing insulin levels Beta cell function must be present Improve sensitivity to insulin in tissues Result in lower blood glucose levels

Oral Antidiabetic Drugs:Mechanism of Action (cont’d)


Glinides Action similar to sulfonylureas Increase insulin secretion from the pancreas



Thiazolidinediones Decrease insulin resistance “Insulin sensitizing drugs” Increase glucose uptake and use in skeletal muscle Inhibit glucose and triglyceride production in the liver



Alpha-glucosidase inhibitors Reversibly inhibit the enzyme alpha-glucosidase in

the small intestine Result in delayed absorption of glucose Must be taken with meals to prevent excessive

postprandial blood glucose elevations (with the “first bite” of a meal)



Dipeptidyl peptidase-IV (DPP-IV) inhibitors Delay breakdown of incretin hormones by inhibiting

the enzyme DPP-IV Incretin hormones increase insulin synthesis and

lower glucagon secretion Reduce fasting and postprandial glucose

concentrations



Used alone or in combination with other drugs and/or diet and lifestyle changes to lower the blood glucose levels in patients with type 2 diabetes

Oral Antidiabetic Drugs:Indications


Biguanides (metformin) Primarily affects GI tract: abdominal bloating, nausea,

cramping, diarrhea, feeling of fullness May also cause metallic taste, reduced vitamin B12

levels Lactic acidosis is rare but lethal if it occurs Does not cause hypoglycemia

Oral Antidiabetic Drugs: Adverse Effects


Sulfonylureas Hypoglycemia, hematologic effects, nausea,

epigastric fullness, heartburn, many others Glinides

Headache, hypoglycemic effects, dizziness, weight gain, joint pain, upper respiratory infection or flulike symptoms

Oral Antidiabetic Drugs: Adverse Effects (cont’d)


Thiazolidinediones Moderate weight gain, edema, mild anemia Hepatic toxicity—monitor alanine aminotransferase

(ALT) levels Alpha-glucosidase inhibitors

Flatulence, diarrhea, abdominal pain Do not cause hypoglycemia, hyperinsulinemia, or

weight gain



Dipeptidyl peptidase-IV (DPP-IV) inhibitors Upper respiratory tract infection, headache, and

diarrhea Hypoglycemia can occur and is more common if

used in conjunction with a sulfonylurea



Amylin agonists pramlintide (Symlin)

Incretin mimetics exenatide (Byetta) liraglutide (Victoza)

Injectable Antidiabetic Drugs


Amylin agonist Mimics the natural hormone amylin Slows gastric emptying Suppresses glucagon secretion, reducing hepatic

glucose output Centrally modulates appetite and satiety Used when other drugs have not achieved adequate

glucose control Subcutaneous injection

Injectable Antidiabetic Drugs: Mechanism of Action (cont’d)


Incretin mimetic Mimics the incretin hormones Enhances glucose-driven insulin secretion from beta

cells of the pancreas Only used for type 2 diabetes Exenatide: Injection pen device

Injectable Antidiabetic Drugs: Mechanism of Action (cont’d)


Amylin agonist Nausea, vomiting, anorexia, headache

Incretin mimetics Nausea, vomiting, and diarrhea Rare cases of hemorrhagic or necrotizing pancreatitis Weight loss

Injectable Antidiabetic Drugs: Adverse Effects


Abnormally low blood glucose level (below 50 mg/dL)

Mild cases can be treated with diet—higher intake of protein and lower intake of carbohydrates—to prevent rebound postprandial hypoglycemia

Hypoglycemia


Early Confusion, irritability, tremor, sweating

Late Hypothermia, seizures Coma and death will occur if not treated

Hypoglycemia Symptoms


Oral forms of concentrated glucose Buccal tablets, semisolid gel

50% dextrose in water (D50W) Glucagon

Glucose-Elevating Drugs


Before giving drugs that alter glucose levels, obtain and document: A thorough history Vital signs Blood glucose level, A1C level Potential complications and drug interactions

Nursing Implications


Before giving drugs that alter glucose levels: Assess the patient’s ability to consume food Assess for nausea or vomiting Hypoglycemia may be a problem if antidiabetic drugs

are given and the patient does not eat If a patient is NPO for a test or procedure, consult

primary care provider to clarify orders for antidiabetic drug therapy

Nursing Implications (cont’d)


Keep in mind that overall concerns for any patient with diabetes increase when the patient: Is under stress Has an infection Has an illness or trauma Is pregnant or lactating



Classroom Response QuestionA patient with type 1 diabetes is admitted to the medical unit with an acute exacerbation of chronic obstructive pulmonary disease (COPD). He is placed on IVPB antibiotics, nebulizer treatments with albuterol, and an IV corticosteroid, and he is also taking a proton pump inhibitor for gastrointestinal esophageal reflux disease (GERD). He takes a dose of glargine insulin every evening. That evening the nurse notes that his blood glucose level is 170 mg/dL. The next morning, his fasting glucose level is 202 mg/dL. What is the most likely cause of his elevated glucose levels?A.The albuterol

B.The antibiotics

C.The proton pump inhibitor

D.The corticosteroid


Thorough patient education is essential regarding: Disease process Diet and exercise recommendations Self-administration of insulin or oral drugs Potential complications




When insulin is ordered, ensure: Correct route Correct type of insulin Timing of the dose Correct dosage

Insulin order and prepared dosages are second-checked with another nurse


Insulin Check blood glucose level before giving insulin Roll vials between hands instead of shaking them to

mix suspensions Ensure correct storage of insulin vials Only use insulin syringes, calibrated in units, to

measure and give insulin Ensure correct timing of insulin dose with meals



Insulin (cont’d) When drawing up two types of insulin in one syringe,

always withdraw the regular or rapid-acting insulin first

Provide thorough patient education regarding self-administration of insulin injections, including timing of doses, monitoring blood glucose levels, and injection site rotations



Classroom Response Question

After the 0700 report, the day shift nurse notices that a patient has a 0730 dose of insulin due and goes to the automated dispensing machine to retrieve the insulin. The nurse sees that the night shift nurse had removed the 0730 dose of insulin, but the medication administration record (MAR) has not been signed by the nurse. The patient is confused and says “she thinks” the night nurse gave her the insulin. The patient’s blood glucose level is 142 mg/dL. What will the day shift nurse do?A.Give the insulin because it was not signed off.

B.Hold the insulin because the patient thinks she received it and it is recorded in the machine.

C.Ask the charge nurse to call the night nurse at home to clarify whether the insulin was given.

D.Report this to the nursing supervisor.


Oral antidiabetic drugs Always check blood glucose levels before giving Usually given 30 minutes before meals Alpha-glucosidase inhibitors are given with the first

bite of each main meal Metformin is taken with meals to reduce GI effects Metformin will need to be discontinued if the patient is

to undergo studies with contrast dye because of possible renal effects—check with the prescriber



Assess for signs of hypoglycemia If hypoglycemia occurs:

Administer oral form of glucose, if the patient is conscious

Give the patient glucose tablets or gel, corn syrup, honey, fruit juice, or nondiet soft drink or have the patient eat a small snack, such as crackers or a half sandwich

Deliver D50W or glucagon intravenously, if the patient is unconscious

Monitor blood glucose levels



Monitor for therapeutic response Decrease in blood glucose levels to the level

prescribed by physician Measure hemoglobin A1C to monitor long-term

compliance with diet and drug therapy Monitor for hypoglycemia and hyperglycemia



Case Study

A male patient who has a history of type 2 diabetes mellitus is admitted to the medical unit with a diagnosis of pneumonia. The patient has many questions regarding his care and asks the nurse why everyone keeps telling him about hemoglobin A1C. The nurse will inform the patient that hemoglobin A1C provides information regarding:A.which type of diabetes the patient has.

B.if he has an infection.

C.patient compliance with treatment regimen for several months previously.

D.current fasting blood glucose level.


Case Study

The patient was taking metformin before this hospitalization. To facilitate better glucose control, the patient has been switched to insulin therapy while hospitalized. The patient asks the nurse why it is so important to time meals with the insulin injection and to give him an example of a long-acting insulin. Which drug will the nurse tell the patient is a long-acting insulin?A.Insulin glulisine (Apidra)

B.Insulin isophane suspension (NPH)

C.Insulin detemir (Levemir)

D.Regular insulin (Humulin R)


Case Study

The patient is being discharged home with insulin aspart (NovoLog) and insulin isophane suspension (NPH). Which information does the nurse include when providing discharge teaching to the patient?A.Store the insulins in the refrigerator

B.Shake the insulins for 1 full minute before use.

C.Administer the injection at a 30-degree angle to your skin.

D.Draw up the insulin aspart (NovoLog) first, then the insulin isophane suspension (NPH) into the same syringe.


Case Study

The nurse enters the patient’s room to complete the discharge process and finds the patient to be lying in bed unresponsive and breathing. The patient has a blood glucose reading of 48 mg/dL. What is the most appropriate response by the nurse?A.Place a packet of table sugar in the patient’s mouth.

B.Start CPR.

C.Roll the patient to the side and administer the ordered glucagon.

D.Have the patient drink orange juice.


Chapter 32 Antidiabetic Drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Documents

imprint of elsevier

diabetes mellitus copyright

insulin therapy type

insulin resistance

pregnancy insulin

insulin deficiency

types type

insulinresistance syndrome