Dental Pharmacology Ch 21

29. Insulin is a pancreatic hormone that promotes insulin storage.

ANS: T Correct: Insulin promotes fuel storage, whereas glucagon promotes fuel mobilization. REF: Pancreatic Hormones | p. 233

3. Insulin resistance develops because of prolonged _____ and resulting _____. a. hyperglycemia; hyperinsulinemia b. hyperglycemia; hypoinsulinemia c. hypoglycemia; hyperinsulinemia d. hypoglycemia; hypoinsulinemia

ANS: A Correct: Tissue insensitivity to insulin, a deficiency of the pancreas's response to glucose, and obesity results in impaired insulin action. In the presence of hyperglycemia, the resistance of the tissues to insulin and the impaired cells' response are exaggerated. Incorrect choices: Hyperglycemia and resulting hyperinsulinemia lead to insulin resistance. REF: Diabetes Mellitus (Type 2) | p. 234

28 Which of the following oral antidiabetic agents is a bile-acid sequestrant used to lower low-density lipoprotein (LDL) cholesterol? a. Pramlintide b. Colesevelam c. DPP-4s d. Glucagon

ANS: B Correct: The mechanism of action of colesevelam in treating type II diabetes is unclear. It has been approved by the FDA as an adjunct to diet and exercise for the treatment of type II diabetes. It can cause constipation, nausea, dyspepsia, and increase serum triglyceride levels. It can interfere with absorption of other oral drugs. Incorrect choices: Colesevelam (WelChol) is a bile-acid sequestrant that is used to lower LDL cholesterol. REF: Drugs Used to Manage Diabetes (Bile Acid Sequestrants) | p. 240

20. The mechanism of action of the sulfonylureas includes _____ of the release of insulin from the beta cells of the pancreas, _____ of glucose from the liver and serum glucagon levels, and a(n) _____ in the sensitivity of the target tissues to insulin. a. stimulation; increase; increase b. stimulation; increase; reduction c. stimulation; reduction; increase d. stimulation; reduction; reduction e. inhibition; reduction; reduction

ANS: C Correct: For many years, the sulfonylureas were the only orally active agents used to manage diabetes. Second-generation sulfonylureas have replaced first-generation sulfonylureas because they are less toxic and easier to dose than first-generation sulfonylureas. Incorrect choices: The mechanism of action of sulfonylureas includes stimulation of the release of insulin from the beta cells of the pancreas, reduction of glucose from the liver and serum glucagon levels, and an increase in the sensitivity of the target tissues to insulin. REF: Drugs Used to Manage Diabetes (Sulfonylureas) | p. 238

10. Which of the following choices is recommended for the treatment of hypoglycemia if the patient is unconscious and lacks a swallowing reflex? a. Fruit juice b. Cake icing c. Intravenous dextrose (50%) d. Glucose gel

ANS: C Correct: Intravenous dextrose (50%) is the treatment of choice for hypoglycemia if the patient is unconscious and lacks a swallowing reflex. Intravenous glucose fluids and glucagon can be administered. Incorrect choices: When the patient is awake in the early stages of hypoglycemia, the treatment consists of any of the following: fruit juice, cake icing, glucose gel, or soluble carbohydrates. REF: Treatment of Hypoglycemia | p. 243

13. Human insulin is made from pork insulin by: a. recombinant DNA synthesis. b. gene splicing in Escherichia coli. c. transpeptidation. d. transamination. e. glycosylation.

ANS: C Correct: Pig insulin has only two amino acids that are different from those in human insulin. The protein can be converted by transpeptidation. Incorrect choices: Recombinant DNA synthesis and gene splicing in E. coli refer to the same process, which is the process for synthesizing human insulin from scratch. Transamination and glycosylation are two biochemical processes that are not used in making human insulin from pork insulin. REF: Drugs to Manage Diabetes (Insulins) | p. 237

16. Which of the following symptoms of hypoglycemia can be explained by glucose deprivation of the brain rather than the adrenal glands: (1) blurred vision, (2) incoherent speech, (3) sweating, (4) tachycardia? a. 1, 2, 3, 4 b. 1, 2, 3 c. 1, 2 d. 3, 4

ANS: C Correct: Symptoms of hypoglycemia caused by glucose deprivation of the brain include headache, blurred vision, mental confusion, incoherent speech, and (eventually) coma, convulsions, and death. Incorrect choices: Symptoms of hypoglycemia that can be explained by an increased release of epinephrine from the adrenals include sweating, weakness, nausea, and tachycardia. REF: Drugs to Manage Diabetes (Insulins) | p. 237

8. Diabetic gastroparesis can be treated with: a. amitriptyline. b. carbamazepine. c. ranitidine. d. metoclopramide.

ANS: D Correct: Diabetic gastroparesis is atony of the gastrointestinal (GI) tract and is a consequence of diabetic neuropathy. It is treated with metoclopramide, which increases gastric motility. Incorrect choices: Amitriptyline is a tricyclic antidepressant. Carbamazepine is an antiepileptic drug. Ranitidine is an H2-receptor antagonist. REF: Diabetes Mellitus (Neuropathy) | p. 236

14. Which form of insulin has a faster onset of action as a consequence of exchanging two amino acids in its structure? a. Pork insulin b. NPH insulin c. Prompt zinc insulin d. Lispro insulin e. Protamine zinc insulin

ANS: D Correct: Lispro, a new insulin, is made by exchanging two amino acids in the structure of human insulin. This change results in an insulin with a faster onset of action. Incorrect choices: Pork insulin differs from human insulin by two amino acids, but it does not have the characteristics of lispro. The other choices have the same peptide sequence as human insulin but are complexed with different ingredients to alter the onset and duration properties of the molecule. REF: Drugs to Manage Diabetes (Insulins) | p. 237

22. Which of the following statements is the mechanism of action of nonsulfonylurea secretagogues such as repaglinide (Prandin) and nateglinide (Starlix)? a. They are competitive, reversible inhibitors of GI tract enzymes: intestinal -glucosidase and pancreatic -amylase. b. They increase the insulin sensitivity of adipose tissue, skeletal muscle, and the liver. c. They increase hepatic and peripheral insulin sensitivity, resulting in decreased hepatic glucose production. d. They bind to adenosine triphosphate (ATP) sensitive potassium channels on beta cells and increase insulin resistance.

ANS: D Correct: Nonsulfonylurea secretagogues, such as repaglinide (Prandin) and nateglinide (Starlix), bind to ATP sensitive potassium channels on beta cells and increase insulin resistance. Incorrect choices: -glucosidase inhibitors are competitive, reversible inhibitors of GI tract enzymes: intestinal -glucosidase and pancreatic -amylase. Thiazolidinediones increase the insulin sensitivity of adipose tissue, skeletal muscle, and the liver. Metformin, a biguanide, increases hepatic and peripheral insulin sensitivity, resulting in decreased hepatic glucose production. REF: Drugs Used to Manage Diabetes (Meglitinides) | p. 238

24. Which oral antidiabetic agent requires administration for 6 to 14 weeks to achieve maximal therapeutic effect? a. Tolbutamide b. Exenatide c. Metformin d. Rosiglitazone e. Glimepiride

ANS: D Correct: Pioglitazone (Actos) and rosiglitazone (Avandia) can take up to 6 to 14 weeks to achieve maximal effect. Incorrect choices: Tolbutamide, metformin, and glimepiride work much more quickly than the thiazolidinediones. Exenatide is not an oral antidiabetic because it is administered subcutaneously. REF: Drugs Used to Manage Diabetes (Thiazolidinediones) | p. 239

9. Contributing factors to gangrene in the extremities of diabetic patients include: a. poor eyesight. b. poor circulation. c. reduced sensation in the extremities. d. all of the above. e. none of the above.

ANS: D Correct: Poor eyesight and reduced sensation in the extremities increase the risk of injury that can lead to infection. Poor circulation makes it more difficult for the immune system and systemic drug therapy to reach the site of infection. Incorrect choices: All of the choices contribute to gangrene in the extremities of diabetic patients. REF: Diabetes Mellitus (Infections) | p. 236

7. Which of the following statements is true regarding systemic complications of diabetes? a. Hypolipidemia is common in patients with diabetes. b. Neuropathy is a complication of diabetes. c. Gangrene can occur in peripheral extremities. d. Both a and b are true. e. Both b and c are true.

ANS: E Correct: Neuropathy is a complication of diabetes. It leads to reduced and sometimes absent feelings, especially in the lower extremities. Gangrene can occur in peripheral extremities, especially the feet and legs. This occurs because of the deficiencies of diabetes, depressed immunity, less effective white blood cells, microvascular changes, and neuropathy. Incorrect choices: Hyperlipidemia and atherosclerosis are more common in these patients. REF: Diabetes Mellitus (Neuropathy) | p. 236 | Diabetes Mellitus (Infections) | p. 236

27. Which of the following statements is true of pramlintide (Symlin)? a. It is an oral dipeptidyl-peptidase-4 (DPP-4) inhibitor. b. Use leads to decreased caloric intake and potential weight loss. c. It is approved for type I diabetes as an adjunct treatment in patients who use mealtime insulin therapy and who have failed to achieve desired glucose control despite optimal insulin therapy. d. Both a and b are true. e. Both b and c are true.

ANS: E Correct: Pramlintide (Symlin) is responsible for modulation of gastric emptying, prevention of the postprandial rise in plasma glucagon, and satiety, which leads to decreased caloric intake and potential weight loss. It is approved for type I diabetes as an adjunct treatment in patients who use mealtime insulin therapy and who have failed to achieve desired glucose control despite optimal insulin therapy. Incorrect choices: Pramlintide is an amylinomimetic agent. Sitagliptin is an oral DPP-4 inhibitor. REF: Drugs Used to Manage Diabetes (Pramlintide) | p. 240

The hemoglobin A1C level should be more than 50% to reduce the incidence and progression of microvascular complications in patients with diabetes.

ANS: F Correct: The American Diabetes Association Standards of Medical Care in Diabetes recommends a hemoglobin A1C level of <7% . REF: Diabetes Mellitus (Goals of Therapy) | p. 237

Acarbose (Precose) slows the breakdown of ingested carbohydrates so that postprandial hyperglycemia is reduced.

ANS: T Correct: Acarbose (Precose) is an -glucosidase inhibitor. It slows the breakdown of ingested carbohydrates so that postprandial hyperglycemia is reduced. REF: Drugs Used to Manage Diabetes (a-Glucosidase Inhibitors) | p. 240

Diabetes is the major cause of blindness in adults.

ANS: T Correct: Because microvascular disease affects the blood supply to the retina, functioning of the retina is impaired in the person with diabetes. REF: Diabetes Mellitus (Retinopathy) | p. 236

More people are diagnosed with type II diabetes in the United States than are diagnosed with type I diabetes.

ANS: T Correct: Nearly 26 million people in the United States have diabetes. The majority of these people, 90% to 95%, are diagnosed with type II diabetes. REF: Diabetes Mellitus | p. 233

The glycosylated hemoglobin test more accurately measures the patient's overall serum glucose control than the serum glucose test.

ANS: T Correct: Serum glucose is a measure of the patient's glucose control at the time that the blood is sampled. It does not reflect the patient's overall glucose control. The glycosylated hemoglobin test more accurately measures the patient's overall serum glucose control because it reflects the glucose control over a 2- to 3-month period. REF: Diabetes Mellitus (Evaluation of the Dental Patient with Diabetes) | p. 237

TRUE OR FALSE

TRUE OR FALSE

23. Acarbose lowers blood glucose by: a. slowing glucose absorption. b. enhancing insulin secretion. c. decreasing hepatic glucose production. d. increasing peripheral glucose uptake.

ANS: A Correct: Acarbose is an -glucosidase inhibitor. Simply stated, it slows the breakdown of ingested fat so that postprandial hyperglycemia is reduced. Incorrect choices: Acarbose works within the GI tract and does not act by enhancing insulin secretion, decreasing hepatic glucose production, or decreasing peripheral glucose uptake. REF: Drugs Used to Manage Diabetes (a-Glucosidase Inhibitors) | p. 240

15. The most common adverse reaction associated with any insulin product is: a. hypoglycemia. b. hyperglycemia. c. intestinal stasis. d. bradycardia.

ANS: A Correct: Besides hypoglycemia, inhaled insulin can cause shortness of breath, dry mouth, and cough. Incorrect choices: The dental health care worker should be most concerned about a hypoglycemic reaction in the dental patient with diabetes who takes insulin. This reaction can be caused by an unintentional overdose of insulin, failure to eat, or increased exercise or stress. REF: Drugs to Manage Diabetes (Insulins) | p. 237

26. Exenatide (Byetta) is the first of a new class of drugs called: a. incretin mimetics. b. oral hypoglycemic agents. c. euglycemic agents. d. oral antidiabetic agents.

ANS: A Correct: Exenatide is indicated as an alternative to starting insulin in patients with type II diabetes who have not achieved adequate control with metformin, a sulfonylurea, or both. Liraglutide (Victoza) is the newest drug in this category. It is also available as a subcutaneous injection. It is indicated for adjunct therapy to diet and exercise in patients with type 2 diabetes. Incorrect choices: Exenatide, an incretin mimetic, has an amino acid sequence similar to human glucagon-like peptide-1 (GLP-1) and in the presence of glucose acts to stimulate insulin secretion.

6. Which of the following statements is true concerning oral surgical procedures for the adult patient with diabetes? a.The procedure should be performed before breakfast, and the patient should have taken regular diabetes medication. b. The procedures should be performed to 2 hours after the patient has eaten a normal breakfast and has taken regular antidiabetes medication. c. The procedure should be performed after lunch, and the patient has taken regular diabetes medication. d. The procedure should be performed after lunch, and the patient should skip regular diabetes medication.

ANS: B Correct: After surgery, the patient should receive an adequate caloric intake to prevent hypoglycemia. With general anesthesia, patients are often told to eat nothing by mouth and should take one half of their usual dose of insulin and receive intravenous 5% glucose in distilled water. Incorrect choices: The patient should eat a normal breakfast and take the regular antidiabetes medication prior to the procedure. REF: Diabetes Mellitus (Issues in Dental Care) | p. 236

11. The primary goal of treating diabetes is to maintain hemoglobin A1C levels: a. at zero. b. as close to normal as possible (<7%). c. at a level of 40%. d. as high as possible.

ANS: B Correct: An abundance of conclusive evidence from long-term, randomized clinical trials has proven that maintaining hemoglobin A1C levels as close to the normal range decreases the incidence and progression of microvascular complications of type 2 diabetes. For every percentage point drop in hemoglobin A1C decreases the risk of microvascular complications by 40%. Incorrect choices: The American Diabetes Association Standards of Medical Care in Diabetes recommends a hemoglobin A1C level <7% in order to reduce the incidence and progression of microvascular and macrovascular complication in patients with both type 1 and type 2 diabetes. REF: Diabetes Mellitus (Goals of Therapy) | p. 237

5. All of the following are likely reasons why diabetics have a higher incidence of periodontal disease except which one? a. Enhanced collagenase activity b. Loss of capillary basement membrane integrity c. Changes in glucose tolerance factor d. Microangiopathy of the tissues e. Altered polymorphonuclear leukocyte (PMN) function

ANS: B Correct: Diabetes causes a thickening of the capillary basement membrane, not a decrease in its integrity, which may compromise the transport and exchange functions of the capillaries. Incorrect choices: Enhanced collagenase activity will enhance the breakdown of connective tissue. Changes in glucose tolerance factor increase glucose levels. Microangiopathy of the tissues impairs circulation. Altered PMN function decreases the innate immune response. All of these are considered candidates for the etiology of diabetes-induced periodontal disease. REF: Diabetes Mellitus (Periodontal Disease) | pp. 235-236

2. More and more cases of type II diabetes are being reported in persons younger than 20 years because of: a. an increased incidence of autoimmune disorders. b. a much more sedentary lifestyle and lack of exercise. c. illicit use of legal drugs. d. environmental changes and global warming.

ANS: B Correct: Fast foods, video games, and television have replaced physical activity, and obesity, a major risk factor for developing type II diabetes, is on the rise. Incorrect choices: More and more cases of type II diabetes in young persons is being attributed to a much more sedentary lifestyle and lack of exercise. REF: Diabetes Mellitus (Type 2) | p. 234

1. Which of the following pancreatic hormones promotes fuel mobilization? a. Insulin b. Glucagon c. Islet amyloid polypeptide (IAPP; amylin) d. Pancreatic peptide

ANS: B Correct: Glucagon promotes fuel mobilization. Incorrect choices: Insulin promotes fuel storage. The functions of IAPP (amylin) and pancreatic peptide have not yet been elucidated. REF: Pancreatic Hormones | p. 233

25. The U.S. Food and Drug Administration (FDA) recommends checking serum alanine aminotransferase (ALT) levels before starting therapy with _____ and periodically thereafter. a. biguanides b. thiazolidinediones c. alpha-glucosidase inhibitors d. nonsulfonylurea secretagogues

ANS: B Correct: Hepatotoxicity has rarely been reported with rosiglitazone and pioglitazone. These drugs should not be used in patients with underlying liver disease or with ALT levels greater than 2.5 times the upper limit of normal. Incorrect choices: The FDA recommends checking serum ALT levels before starting therapy with thiazolidinediones and periodically thereafter. REF: Drugs Used to Manage Diabetes (Thiazolidinediones) | p. 240

19. Adverse reactions to metformin occur primarily in the: a. pancreas. b. GI tract. c. oral cavity. d. cardiovascular system.

ANS: B Correct: Lactic acidosis, the most serious side effect with metformin, is rare. Predisposing factors to lactic acidosis include alcoholism, binge drinking, and renal or hepatic dysfunction. Incorrect choices: Adverse reactions are primarily related to the GI tract (30%) and include anorexia, dyspepsia, flatulence, nausea, and vomiting. It can produce headache and interfere with vitamin B12 absorption. It accumulates in renal and hepatic impairment. REF: Drugs Used to Manage Diabetes (Biguanides) | p. 238

17. Which of the following statements is true of metformin? a. It is a member of the -glucosidase inhibitor group of antidiabetic agents. b. It lowers blood glucose but, used alone, does not produce hypoglycemia. c. It decreases hepatic and peripheral insulin sensitivity, resulting in increased hepatic glucose production. d. Lactic acidosis is a common, but benign side effect.

ANS: B Correct: Metformin (Glucophage) lowers blood glucose but, used alone, does not produce hypoglycemia. Incorrect choices: Metformin is a member of the biguanide group of antidiabetic agents. It increases hepatic and peripheral insulin sensitivity, resulting in decreased hepatic glucose production. It also increases peripheral skeletal muscle glucose uptake. Lactic acidosis, its most serious side effect, is rare. REF: Drugs Used to Manage Diabetes (Biguanides) | p. 238

18. Which oral antidiabetic agent produces lactic acidosis as a significant adverse effect? a. Tolbutamide b. Metformin c. Repaglinide d. Acarbose e. Pioglitazone

ANS: B Correct: The biguanides, such as metformin, can cause lactic acidosis as a side effect. Metformin is contraindicated in patients who have these conditions or are fasting. Incorrect choices: Tolbutamide (Orinase) is a sulfonylurea, repaglinide (Prandin) is a meglitinide, acarbose is an -glucosidase inhibitor, and pioglitazone (Actos) is a thiazolidinedione. REF: Drugs Used to Manage Diabetes (Biguanides) | p. 238

12. Insulin is usually administered: a. orally. b. by subcutaneous injection. c. by intramuscular injection. d. by intravenous injection.

ANS: B Correct: The major differences among the currently used types of insulin are their onset and duration of action. Incorrect choices: Insulin is usually administered by subcutaneous injection. Its large molecular size prevents it from being absorbed from the GI tract. REF: Drugs to Manage Diabetes (Insulins) | p. 237

4. Type I and type II diabetics are at greater risk for caries. This risk is attributed to the higher concentration of glucose in their saliva. a. Both statements are true. b. Both statements are false. c. The first statement is true; the second statement is false. d. The first statement is false; the second statement is true.

ANS: C Correct: The increased risk that a diabetic has for caries is due to xerostomia. A decrease in salivary flow can lead to mouth ulcers, inflamed tongue or mucosal tissues, and tooth deterioration. The complications of xerostomia are a result of the lack of its normal functions: lubricating, cleansing, regulating pH, destroying microorganisms and their products, and maintaining the integrity of oral structures. Incorrect choices: Uncontrolled diabetes produces a pronounced susceptibility to dental caries, which is caused mainly by decreased salivary flow (xerostomia) related to fluid loss. The loss is secondary to an increase in urination that occurs because of poor utilization of carbohydrates and the glucose that is excreted via the kidneys (water follows glucose). REF: Diabetes Mellitus (Dental Implications of Diabetes) | pp. 234-235

21. Which of the following types of medications can react with sulfonylureas to produce a decrease in serum glucose levels? a. Penicillin b. Methotrexate c. Aspirin d. Mepivacaine

ANS: C Correct: The interaction between sulfonylureas and aspirin is not clinically significant unless the diabetic patient is especially brittle. Brittle diabetes means the diabetes is difficult to control. Incorrect choices: Aspirin can interact with sulfonylureas to produce a decrease in serum glucose levels. REF: Drugs Used to Manage Diabetes (Sulfonylureas) | p. 238