PH 18 Drug Therapy for Diabetes PDF

17 Drug Therapy for Diabetes LEARNING OUTCOMES 1. Describe the differences between diabetes mellitus type 1 and type 2, and explain why most drugs used for diabetes type 2 are not useful for diabetes type 1. 2. List the names, actions, possible side effects, and adverse effects of the insulin stimu...

17 Drug Therapy for Diabetes LEARNING OUTCOMES 1. Describe the differences between diabetes mellitus type 1 and type 2, and explain why most drugs used for diabetes type 2 are not useful for diabetes type 1. 2. List the names, actions, possible side effects, and adverse effects of the insulin stimulators and the biguanides. 3. Explain what to teach patients and families about the insulin stimulators and the biguanides. 4. List the names, actions, possible side effects, and adverse effects of the insulin sensitizers and the alpha-glucosidase inhibitors. 5. Explain what to teach patients and families about the insulin sensitizers and the alphaglucosidase inhibitors. 6. List the names, actions, possible side effects, and adverse effects of the incretin mimetics and the amylin analogs. 7. Explain what to teach patients and families about the incretin mimetics and the amylin analogs. 8. List the names, actions, possible side effects, and adverse effects of the DPP-4 inhibitors and the sodium-glucose cotransport inhibitors. 9. Explain what to teach patients and families about the DPP-4 inhibitors and the sodium-glucose cotransport inhibitors. 10. List the names, actions, possible side effects, and adverse effects of insulin preparations. 11. Explain what to teach patients and families about insulin preparations. KEY TERMS alpha-glucosidase inhibitor (ĂL-fah glū-KŌ-sĕ-dās ĭn-HĬ-bă-tĕr, p. 315) A category of oral non-insulin antidiabetic drugs that lowers blood glucose levels by preventing enzymes in the intestinal tract from breaking down starches and more complex sugars into glucose. amylin analog (Ă-mĕ-lĕn Ă-nĕ-lŏg, p. 317) A category of injectable non-insulin antidiabetic drugs similar to natural amylin, which is a hormone produced by pancreatic beta cells that works with and is co-secreted with insulin in response to blood glucose elevation. It prevents hyperglycemia by delaying gastric emptying and making the patient feel full so he or she eats less. biguanides (bī-GWŎN-īd, p. 314) A category of oral non-insulin antidiabetic 571 drugs that lowers blood glucose levels by reducing the amount of glucose the liver releases and by reducing how much and how fast the intestines absorb the glucose in food. diabetes mellitus (DM) (dī-ĕ-BĒ-tēz MĔ-lĕ-tĕs, p. 310) A common chronic endocrine problem in which either the lack of insulin or poor function of insulin impairs glucose metabolism, which then leads to problems in fat metabolism and protein metabolism. DPP-4 (dipeptidyl peptidase-4) inhibitors (p. 318) A category of non-insulin antidiabetic drugs that helps prevent hyperglycemia by reducing the amount of the enzyme (DPP-4), which inactivates the normal incretins, GLP and GIP. This actions allow the naturally produced incretins to be present and work with insulin to control blood glucose levels. glucagon (p. 310) A hormone produced by alpha cells of the pancreas that works to raise the concentration of glucose and fat in the bloodstream. glucose (GLŪ-kōs, p. 310) A sugar-based nutrient critically important for energy production in cells and organs. hyperglycemia (hī-pĕr-glī-SĒ-mē-ĕ, p. 311) A condition of higher-than-normal blood glucose levels. hypoglycemia (hī-pō-glī-SĒ-mē-ĕ, p. 310) A condition of lower-than-normal blood glucose levels. incretin mimetics (ĭn-KRĒ-tĭn mĭ-MĔ-tĭks, p. 316) A category of non-insulin antidiabetic drugs that acts like the natural gut hormones (e.g., GLP-1) that are secreted in response to food in the stomach. They work with insulin to prevent blood glucose levels from becoming too high after meals by slowing the rate of gastric emptying. insulin (ĬN-sŭ-lĭn, p. 310) A protein hormone produced by the pancreas or injected as a drug that binds to insulin receptors on many cells, which then promotes the movement of glucose from the blood into the cells. insulin sensitizer (ĬN-sŭ-lĭn SĔN-sĭ-tīz-ĕr, p. 314) A category of oral non-insulin antidiabetic drugs that lowers blood glucose levels by making insulin receptors more sensitive to insulin, which increases cellular uptake and use of glucose. insulin stimulator (ĬN-sŭ-lĭn STĬM-ū-lā-tĕrs, p. 312) A category of oral non-insulin antidiabetic drugs that lowers blood glucose levels by triggering the release of insulin stored in the beta cells of the pancreas. The sulfonylureas and the meglitinides are the two classes of drugs in this category. non-insulin antidiabetic drugs (p. 312) Oral and injectable drugs that use a variety of mechanisms other than binding to insulin receptors to help lower blood glucose levels back to the normal range. sodium-glucose cotransport inhibitor (SŌ-dē-em GLŪ-kōs kō-TRĂNS-pōrt ĭn-HĬbă-tĕrz, p. 320) A category of non-insulin antidiabetic drug that lowers blood glucose levels by preventing the kidney from reabsorbing glucose that was filtered from the blood into the urine. This glucose then remains in the urine and is excreted rather than moved back into the blood. 572 Diabetes Blood Glucose Control Glucose is a sugar-based nutrient that is critical for energy production in cells and organs. Insulin is a protein hormone produced by the pancreas that binds to insulin receptors on many cells. Like other hormones, insulin is a “key” that binds to its receptors (the “locks”). When insulin binds to its receptors, the “doors” on cell membranes open for glucose to enter cells, which lowers the blood glucose level. Glucose in the cells undergoes metabolism to generate the cellular energy needed to perform all functions, particularly organ physiologic functions. When blood glucose levels are lower than normal (hypoglycemia), glucose is not available for cells and organs to metabolize it into energy substances, and cellular function can be greatly reduced. However, too much glucose leads to the many serious complications of diabetes mellitus (DM). So good glucose control, sometimes called glycemic control, requires balancing blood glucose so levels are constantly in the normal range. Table 17.1 lists the desired laboratory values that indicate good blood glucose control for the two most common tests (fasting blood glucose levels and hemoglobin A1c). Table 17.1 Goals for Blood Glucose Control LABORATORY TEST INDICATIONS OF GOOD BLOOD GLUCOSE CONTROL Fasting blood glucose Less than 100 mg/dL or 5.6 mmol/L Controlled levels for older adults usually increase by about 1.0 mg/dL or 0.05 mmol/L for every decade of life 4%–6% Glycosylated hemoglobin (A1c), also known as hemoglobin A1c The healthy pancreas controls blood glucose levels through the actions of insulin and another hormone, glucagon. Insulin prevents hyperglycemia by allowing body cells to take up, use, and store carbohydrate, fat, and protein. It is known as the “hormone of plenty” because its release is triggered by a high blood glucose level. Glucagon is a hormone that has actions opposite those of insulin. It prevents low blood glucose levels by triggering the release of glucose from storage sites in the liver and skeletal muscle. Glucagon is known as the “hormone of starvation” because the trigger for its release is a lower-than-normal blood glucose lever. When these two hormones are released appropriately, blood glucose levels remain in the normal range. Memory Jogger Insulin is the hormone of plenty, which is released when blood glucose levels are above normal. Its function is to lower blood glucose levels and prevent hyperglycemia. Glucagon is the hormone of starvation, which is released when blood glucose levels are lower than normal. Its function is to raise blood glucose levels and prevent hypoglycemia. In addition to insulin and glucagon, other organs and hormones help maintain 573 normal blood glucose levels by balancing glucose uptake by cells and glucose production by the liver. Blood glucose levels after a meal are controlled by the emptying rate of the stomach and delivery of nutrients to the small intestine, where they are absorbed into circulation. Incretin hormones (e.g., glucagon-like peptide-1 [GLP-1]), secreted in response to food in the stomach, work with insulin to prevent blood glucose levels from becoming too high after meals. The actions of incretins increase insulin secretion, inhibit glucagon secretion, and slow the rate of gastric emptying. All of these actions help prevent high blood glucose levels. The neurons and the brain require a continuous supply of glucose from the blood because the brain cannot store it. Other organs can use fats, as well as glucose, to generate energy. In the liver and muscles, glucose is stored as glycogen. Fats are stored as triglyceride in fat cells. During a prolonged fast or after illness, proteins are broken down and some of the amino acids are converted into glucose. Insulin not only keeps blood glucose levels from becoming too high, it also helps keep blood lipid levels in the normal range and prevents muscle protein breakdown. Loss of Glucose Control Diabetes mellitus is a common chronic endocrine problem in which either the lack of insulin or poor function of insulin impairs glucose metabolism. When glucose metabolism is poor, problems in fat metabolism and protein metabolism also occur. When there is not enough insulin or when insulin does not bind well to its receptor, glucose does not enter cells and circulates unused and at high levels in the blood. So the main feature of DM is chronic high blood glucose levels (hyperglycemia) because glucose movement from the blood into cells and organs is impaired. Memory Jogger The main feature of DM is chronic high blood glucose levels (hyperglycemia) because glucose movement from the blood into cells and organs is impaired. About 29 million people in the United States and 2 million people in Canada are living with DM. Nearly one-third of people with diabetes have not been diagnosed and are not being treated. Another 90 million have prediabetes, which is abnormal glucose metabolism that has a high risk for developing into actual DM. DM that is not well controlled can reduce the function of all organs and tissues. Complications of uncontrolled or poorly controlled DM include hypertension, high blood lipid levels, early-onset cardiovascular disease, kidney failure, strokes, and blindness, to name only the more serious ones. The complications of DM can be delayed or reduced with good blood glucose (glycemic) control, along with keeping blood pressure and blood cholesterol levels as close to normal as possible. The lack of insulin production or a problem with insulin binding to its cell receptors prevents some cells from using glucose for energy. The body then breaks down fat and protein in an attempt to provide energy and increases the production of glucose from other sources. Muscle protein is reduced, and the body uses fats in the blood in place of glucose for cellular energy. When this stored fat is used for energy, ketoacids are formed and collect in the blood, resulting in a dangerous and 574 potentially fatal condition known as ketoacidosis. The classic symptoms of DM are polydipsia (increased fluid intake), polyuria (excessive urination), and polyphagia (hunger with excessive eating). The person with untreated DM remains in metabolic starvation until insulin is available to move glucose into the cells. Memory Jogger Hyperglycemia Early Signs • Frequent urination • Increased thirst • Dry mouth • Blurred vision • Fatigue • Headache Late Signs • Fruity-smelling breath • Abdominal pain • Nausea and vomiting • Shortness of breath • Weakness • Confusion • Coma Classification of Diabetes Mellitus In addition to the diabetes that can occur with pregnancy (gestational diabetes), there are two main types of DM. Diabetes mellitus (DM type 1) is an autoimmune disorder in which the beta cells of the pancreas that store and release insulin are destroyed when a person's own immune system takes destructive actions and produces antibodies against the insulin-secreting cells in the pancreas. This immune attack can be caused by a genetic predisposition or exposure to certain viruses. This most commonly begins after a viral infection such as mumps and coxsackievirus infection. Often DM type 1 is diagnosed in childhood, sometimes even before the child is a year old. Older names for DM type 1 are insulin-dependent diabetes mellitus (IDDM) or juvenile diabetes. With DM type 1, the pancreas produces no insulin. The patient must take insulin daily for life unless a pancreas transplant is received. Diabetes mellitus type 2 (DM type 2) is a disorder in which the person continues to make some insulin, but it does not bind well to its receptors so there is a reduced response of the body to insulin, known as insulin resistance. Eventually, the pancreas 575 makes less and less insulin. Insulin resistance develops from obesity and decreased physical activity in people who are genetically predisposed. Obesity is a common finding in many, but not all, patients with DM type 2. Usually DM type 2 develops in adulthood, although with childhood obesity on the rise, some children are also being diagnosed with it. Older names for DM type 2 are non-insulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes. About 90% of people with DM have diabetes type 2. The pancreas still makes some insulin, so the symptoms occur over a long time and many people are not aware they have the disease until long-term complications begin. So far fewer people have DM type 1, although it is usually diagnosed more quickly because the initial symptoms are so sudden and severe. It is important to remember that whether a person has DM type 1 or type 2, the long-term complications are the same and often shorten the person's lifespan. Bookmark This! The American Diabetes Association: http://www.diabetes.org Drug Therapy for Diabetes Mellitus Non-Insulin Antidiabetic Drugs Patients with DM type 2 usually have a pancreas that functions a little and can be stimulated by drugs to produce more insulin. Drug therapy can also improve how well insulin interacts with its receptors. Insulin may also be necessary for some people with DM type 2, although diet, weight reduction, and non-insulin antidiabetic drugs are often effective in maintaining good blood glucose control. Non-insulin antidiabetic drugs are oral and injectable drugs that use a variety of mechanisms other than binding to insulin receptors to help lower blood glucose levels back to the normal range. At one time some of these drugs were called oral hypoglycemic agents, although this term was never correct. The goal of drug therapy for DM type 2 is to help keep blood glucose levels within the normal target range for each person, not to make the person hypoglycemic. In fact hypoglycemia is a serious adverse effect of some of these drugs, not the desired effect. Non-insulin antidiabetic drugs are prescribed when diet and exercise alone are not enough for a patient with DM type 2 to maintain the blood glucose target range identified for him or her. These drugs are not a substitute for diet and exercise for blood glucose control, but are used in addition to them. Usually one drug is started at the lowest effective dose and increased every 1 to 2 weeks until the patient either reaches his or her target blood glucose levels or the maximum drug dose is reached without the desired blood glucose control. If the first drug does not adequately control blood glucose levels, a second non-insulin antidiabetic drug that works differently may be added to the first or used alone. Insulin therapy is used only when blood glucose target ranges cannot be met with the use of two or three different types of non-insulin antidiabetic agents. The non-insulin antidiabetic drugs are divided into eight categories. These categories are the insulin stimulators (secretogogues, which include the sulfonylureas 576 and the meglitinide analogs), the biguanides, the insulin sensitizers, the alphaglucosidase inhibitors, the incretin mimetics, the DPP-4 (dipeptidyl peptidase-4) inhibitors, the amylin analogs, and the sodium-glucose cotransport inhibitors. Some are oral agents and others are taken by subcutaneous injection. The drug tables in this chapter list the mechanisms of action, usual adult dosages, nursing implications, and common drugs for each class. Memory Jogger The eight categories of non-insulin antidiabetic drugs are: • insulin stimulators (secretogogues) • biguanides • insulin sensitizers • alpha-glucosidase inhibitors • incretin mimetics • amylin analogs • DPP-4 inhibitors • sodium-glucose cotransport inhibitors Insulin Stimulators (Secretogogues) Action and Uses Insulin stimulators are oral drugs that lower blood glucose levels by stimulating the release of insulin stored in the beta cells of the pancreas. Therefore the patient must have some functioning beta cells if these drugs are to work. In addition, they improve the movement of glucose into cells by either increasing the number of insulin receptors present on the cells or by enhancing the actions of activated insulin receptors. They are used only for DM type 2 and are often used with other noninsulin antidiabetic drugs for best blood glucose control. They also can be used with insulin. The sulfonylureas and the meglitinides are the two classes of drugs in this category. Names, usual adult dosages, and nursing implications of the insulin stimulators are listed in Table 17.2. Be sure to consult a drug reference book for more information about specific insulin stimulators. Table 17.2 Examples of Insulin Stimulators and Biguanides Insulin stimulators: drugs that lower blood glucose levels by triggering the release of preformed insulin from beta cells DRUG/ADULT DOSAGE RANGE NURSING IMPLICATIONS Second-Generation Sulfonylurea • Assess patients for indications of hypoglycemia before giving an insulin stimulator, to prevent increasing the Agents risk for hypoglycemia. glimepiride (Amaryl, Apo-Glimepiride • Avoid giving the drug until the patient has his or her food tray, to prevent hypoglycemia. • If a patient is NPO or is not eating a meal, do not give that dose of the insulin stimulator, to prevent ) 1–4 mg orally once daily with hypoglycemia. breakfast • Teach patients the indications of hypoglycemia (i.e., hunger, headache, tremors, sweating, and confusion) glipizide (Glucotrol) 10–15 mg orally because all insulin stimulators lower blood glucose levels even when hyperglycemia is not present. once daily before breakfast glyburide (DiaBeta, Micronase) 0.75–12 • Instruct patients to take these drugs with or just before meals to prevent hypoglycemia. • Instruct patients taking a sulfonylurea to check with his or her healthcare provider or a pharmacist before mg orally daily taking any supplements, over-the-counter drugs, or prescribed drugs because sulfonylureas interact with Meglitinide Analogs 577 nateglinide (Starlix) 120 mg orally three many other drugs. times daily with meals • Warn patients about the common side effects of sulfonylureas (i.e., nausea, headache, and weight gain) to repaglinide (Prandin) 0.5–4 mg orally ensure they are prepared for these effects and are not anxious. with meals up to four times daily Biguanides: drugs that lower blood glucose levels by reducing the amount of glucose the liver releases and by reducing how much and how fast the intestines absorb the glucose in food DRUG/ADULT DOSAGE RANGE NURSING IMPLICATIONS metformin (Glucophage, Glumetza) • Check with the healthcare provider about stopping the drug 24 hours before and for 48 hours after a test using Immediate release: 500–850 mg a radioactive dye is scheduled, to reduce the risk for an interaction that can cause kidney damage. orally twice daily with meals • Teach patients not to cut, crush, or chew the extended-release capsule, to prevent rapid absorption of the drug Extended release: 500–2000 mg orally that could lead to adverse effects. once daily with evening meal Indicates Canadian drug. The sulfonylureas were the first type of non-insulin antidiabetic drugs available to help manage DM type 2. These early drugs, known as first-generation sulfonylureas, are rarely used today because of the extensive number of drug interactions associated with them. The second-generation sulfonylureas are much more potent than first-generation drugs and have fewer interactions with other drugs. The meglitinide analogs are newer insulin stimulators. They work in the same way as sulfonylureas but are more likely to increase insulin release just after a meal, when it is most needed. Expected Side Effects Some common side effects of sulfonylureas are heartburn, nausea, vomiting, abdominal pain, and diarrhea caused by increased gastric acid secretion. In addition, they increase sun sensitivity (photosensitivity), which increases the risk for severe sunburns. Common side effects of meglitinides are upper respiratory infections, back and joint pain, and dizziness. Adverse Effects All of the insulin stimulators can cause hypoglycemia because they force the pancreas to secrete insulin even when blood glucose levels are normal or low. A serious problem with insulin stimulators is that over long periods of use they eventually cause the beta cells of the pancreas to stop producing insulin, a condition known as secondary beta cell failure. In addition, all of these drugs can affect the liver and increase liver enzyme levels. Memory Jogger Indications of Hypoglycemia • Headache • Hunger sensation • Difficulty concentrating • Nervousness • Tremors • Increased sweating • Pale, clammy skin 578 • Rapid heart rate • Anxiety, confusion Drug Interactions Sulfonylureas and the meglitinides interact with many other drugs. Some drugs or drug groups enhance the hypoglycemic effect of insulin stimulators. These include aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), angiotensin II receptor antagonists (ARBs), angiotensin converting enzyme inhibitors (ACEIs), beta blockers, warfarin, azole antifungal drugs, and many antibiotics. Other common drugs, such as corticosteroids, furosemide, isoniazid, pseudoephedrine, antiretroviral protease inhibitors, and thiazide diuretics, increase the hyperglycemia risk by reducing the effectiveness of insulin stimulators. Be sure to consult a drug reference book or pharmacist for more information about specific drug interactions with sulfonylureas and the meglitinides. Top Tip for Safety Drug Interactions Sulfonylureas may decrease the effectiveness of certain contraceptive drugs. Women of childbearing years who are taking this antidiabetic drug will need an alternative contraceptive method to avoid an unplanned pregnancy. Nursing Implications and Patient Teaching Planning and implementation. Assess patients for any signs or symptoms of hypoglycemia before giving an insulin stimulator to avoid making hypoglycemia worse. Signs of hypoglycemia include tremors, sweating, confusion, rapid heart rate, hunger, headache, nervousness, and inability to concentrate. If any indications are present, check the patient's blood glucose level. Do not give an insulin stimulator at the same time as other drugs known to increase the hypoglycemic effect. When in doubt, consult a drug reference book or pharmacist for which other drugs increase hypoglycemic effects. Ensure that these drugs are given with a meal or no more than 15 minutes before a meal to prevent hypoglycemia. It is a good idea to wait until the patient's tray is actually in his or her room before giving the drug. If the patient is NPO or is not eating a meal for some other reason, do not give the drug. Top Tip for Safety Do not give an insulin stimulator drug to a patient who is NPO or who is skipping a meal. 579 Patient and family teaching. Tell the patient and family the following: • Take these drugs with or just before meals to prevent hypoglycemia. If you must skip a meal, also skip the drug dose. • Signs and symptoms of hypoglycemia, which include feelings of hunger, nervousness, confusion, sweating, and tremors. • Check with your healthcare provider or a pharmacist before taking any supplements, over-the-counter drugs, or other prescribed drugs because these drugs interact with many other drugs that can change your blood glucose levels. • Common but expected side effects of these drugs are nausea, headache, and weight gain. Biguanides Action and Uses Biguanides are oral, non-insulin antidiabetic drugs that lower blood glucose levels by reducing the amount of glucose the liver releases and by reducing how much and how fast the intestines absorb the glucose in food. In addition, biguanides also increase how well insulin binds to its cellular receptor site. Unlike the insulin stimulators, biguanides do not force the pancreas to release insulin from its beta cells. The only drug in this class is metformin. The dosages and nursing implications for this drug are presented in Table 17.2. Expected Side Effects The most common side effects of metformin are related to the gastrointestinal (GI) system and include nausea, diarrhea, flatulence, and weight loss. These side effects usually decrease over time. Adverse Effects Metformin use is associated with a risk for lactic acidosis, an unusually high concentrate of lactate in the body. Signs of lactic acidosis include nausea, vomiting, rapid, deep breathing, and weakness. When used without other antidiabetic drugs, metformin alone does not cause hypoglycemia. Drug Interactions Metformin interacts with the dye (contrast medium) used in some diagnostic tests 580 and can lead to kidney failure. For this reason, metformin is to be stopped at least 24 hours before radioactive dye is used and not started again until 48 hours after the test is completed. Nursing Implications and Patient Teaching Planning and implementation. Assess the patient's kidney function. Metformin should not be given to patients with kidney disease because it can cause kidney failure. Assess the patient for signs of lactic acidosis and report any concerning findings to the healthcare provider. Check the patient's blood sugar as ordered, and assess the patient for signs of hypoglycemia. Metformin is safe in pregnancy for the treatment of gestational diabetes. Patient and family teaching. Tell the patient and family the following: • Avoid drinking alcohol while taking metformin because this can increase the chance of developing lactic acidosis. • The common side effects of metformin are mostly GI upset; nausea, vomiting, and diarrhea may occur, especially when the drug is first started or the dose is increased. • Check with your healthcare provider about stopping metformin at least 24 hours before radiopaque dye is used, and not restarting it again until 48 hours after the test is completed. • Keep all appointments for laboratory tests to check homocysteine and vitamin B12 levels because metformin increases homocysteine levels (and increases the risk factor for cardiovascular disease) and may cause vitamin B12 deficiency. Top Tip for Safety Metformin should be stopped 24 hours before any diagnostic tests that use radiopaque dye. Metformin should not be restarted until 48 hours after the test is completed. 581 Insulin Sensitizers Action and Uses Insulin sensitizers are a category of oral non-insulin antidiabetic drugs that lower blood glucose levels by making insulin receptors more sensitive to insulin, which increases cellular uptake and use of glucose. The drugs in this class are the thiazolidinediones, also called the “glitazones” or TZDs. They are used only for DM type 2 and are often used together with other non-insulin antidiabetic drugs for best blood glucose control. They also can be used with insulin. The names, usual adult dosages, and nursing implications of the glitazones are listed in Table 17.3. Table 17.3 Examples of Insulin Sensitizers and Alpha-Glucosidase Inhibitors Insulin sensitizers: drugs that lower blood glucose levels by making insulin receptors more sensitive to insulin, which increases cellular uptake and use of glucose DRUG/ADULT DOSAGE RANGE NURSING IMPLICATIONS pioglitazone (Actos) Initial dosage: 15–30 mg orally daily with meal; • Teach patients to report indications of allergic reactions (itching, hives, facial may increase up to 45 mg daily maximum swelling) immediately to the healthcare provider. rosiglitazone (Avandia) Initial dosage: 4 mg orally once daily or • Monitor patients carefully for signs and symptoms of heart failure (e.g., divided into 2 mg every 12 hours; may increase to 8 mg orally once excessive, rapid weight gain, dyspnea, and/or edema) because these drugs have daily, or divided and given every 12 hours been known to cause or worsen heart failure symptoms. • Monitor for symptoms of hypoglycemia (i.e., hunger, sweating, pale skin, irritability, dizziness, feeling shaky, or trouble concentrating). Alpha-glucosidase inhibitors: non-insulin antidiabetic drugs that lower blood glucose levels by preventing enzymes in the intestinal tract from breaking down starches and more complex sugars into glucose DRUG/ADULT DOSAGE RANGE NURSING IMPLICATIONS acarbose (Prandase, Precose) Initial dosage: 25 mg orally three times • Assess the patient for signs of an allergic reaction to the drug. daily at meals, with a maximum dosage of 100 mg orally three • Monitor the patient for hypoglycemia especially when combined with insulin or times daily other diabetic drugs. miglitol (Glyset) Initial dosage: 25 mg orally every 8 hours at meals; • Monitor the patient for GI discomfort or diarrhea, and report findings to the maintenance dosage: 50 mg orally every 8 hours, with a maximum healthcare provider. GI side effects are common because the intestinal tract is the dosage of 100 mg orally every 8 hours site of action for these drugs. • Take these drugs at the start of a meal because their antidiabetic action is to reduce the conversion of the ingested complex carbohydrates into glucose. Expected Side Effects Hypoglycemia is a potential side effect of rosiglitazone, as well as all agents to treat diabetes, and can be more frequent and severe if combined with the use of insulin as part of the diabetes treatment plan. Headache, sneezing, and sore throat can also occur. Adverse Effects Thiazolidinediones have been associated with severe cardiovascular side effects and must be used with care. Currently, rosiglitazone is a drug only available to selected patients, but pioglitazone is still generally available, although closely monitored. Rosiglitazone can also cause fluid retention, liver problems, and macular edema. Drug Interactions Rosiglitazone has many drug interactions. Gemfibrozil, rifampin, and drugs to treat hypertension can all interact with rosiglitazone. Check your drug reference guide or ask a pharmacist about specific drug interactions. Nursing Implications and Patient Teaching 582 Planning and implementation. Assess the patient for signs of allergic reaction (e.g., hives, facial swelling, and itching). Assess the patient for signs of heart failure, which include weight gain, shortness of breath, tachycardia, and edema. Assess for symptoms of hypoglycemia (e.g., hunger, sweating, pale skin, irritability, dizziness, feeling shaky, or trouble concentrating). Patient and family teaching. Tell the patient and family the following: • Take the drug as prescribed. If you miss a dose, take it as soon as possible. Do not double up on the drug to make up for missed doses. • Report itching, hives, or swelling of the face or hands to your healthcare provider immediately should any of these symptoms of allergic reaction occur. • Report any changes in vision or blurred vision to your healthcare provider. • Report swelling of the feet or ankles, or rapid weight gain to your healthcare provider. • Avoid alcohol because this can affect blood glucose levels, causing both hypoglycemia and hyperglycemia depending on how much alcohol is ingested. • When signs and symptoms of hypoglycemia are present (e.g., hunger, sweating, pale skin, irritability, dizziness, feeling shaky, or trouble concentrating), eat or drink something that contains real sugar, as your healthcare provider directed. • When signs or symptoms of hyperglycemia such as headache, increased thirst, dry mouth, blurred vision, fatigue, abdominal pain, or weakness are present and persist, notify your healthcare provider. • Check your blood sugar frequently, especially during times of stress or illness, because these problems can affect blood glucose levels. Alpha-Glucosidase Inhibitors 583 Action and Uses Alpha-glucosidase inhibitors are a category of oral non-insulin antidiabetic drugs that lower blood glucose levels by preventing enzymes in the intestinal tract from breaking down starches and more complex sugars into glucose. This action slows glucose absorption. These drugs are primarily prescribed for patients who have high blood sugars following meals. Alpha-glucosidase inhibitors were first approved to help manage DM type 2 but can also be used for DM type 1 (along with insulin) because they work in the GI tract independently from insulin. Used alone they cannot cause hypoglycemia. Alphaglucosidase inhibitors can be used with sulfonylureas, insulin, or metformin. The names, usual adult dosages, and nursing implications of the alpha-glucosidase inhibitors are listed in Table 17.3. Expected Side Effects Because alpha-glucosidase inhibitors prevent the breakdown of complex carbohydrates (starches such as bread, cereals, corn, and potatoes) into glucose, the carbohydrates remain in the intestine, causing gas formation (flatulence), feeling bloated, and diarrhea. These side effects usually go away as the body adjusts to the drug and dose. Adverse Effects Alpha-glucosidase inhibitors can cause the worsening of conditions associated with inflammation of the bowel, such as colitis, Crohn's disease, or intestinal obstruction. There is the potential for hypoglycemia when alpha-glucosidase inhibitors are given with insulin or other drugs for the treatment of diabetes. These drugs can cause liver impairment with elevated liver enzyme levels. Drug Interactions There is a risk for hypoglycemia when alpha-glucosidase inhibitors are combined with other diabetes drugs such as sulfonylureas, insulin, and meglitinides. Nursing Implications and Patient Teaching Planning and implementation. Assess the patient for signs of allergic reaction to the drug (e.g., hives, itching, and facial swelling). Monitor the patient for any signs or symptoms associated with hypoglycemia when combined with insulin or other diabetic drugs. Monitor the patient for GI discomfort or diarrhea, and report findings to the healthcare provider because a dose adjustment may be needed. Patient and family teaching. Tell the patient and family the following: • These drugs work best when they are used in conjunction with diet and exercise. 584 • Alpha-glucosidase inhibitors must be taken at the start of meals to get the most benefit because these drugs work by interfering with digestive enzymes. • The drug effect on blood sugar levels after meals will depend on the amount of complex carbohydrates in the meal. • Avoid alcohol because it can increase the risk for liver impairment while taking these drugs. • Report any signs of allergic reaction to the healthcare provider immediately. Incretin Mimetics Action and Uses Incretin mimetics are injectable drugs that act like the natural gut hormones (e.g., glucagon-like peptide-1 [GLP-1]) that are secreted in response to food in the stomach. Just like the gut hormone, these drugs work with insulin to prevent blood glucose levels from becoming too high after meals. This results in an increase in insulin secretion, a decrease in glucagon secretion, and a slower rate of gastric emptying. All of these actions help prevent high blood glucose levels. In addition, these drugs make the person feel full (have satiety), which may help them to eat less. These injected drugs work with naturally secreted insulin, so they are only approved for use in patients who have DM type 2 that has not been controlled with oral drugs. These drugs are given by the subcutaneous route, and some are long-acting, needing only weekly dosing. The names, usual adult dosages, and nursing implications of the incretin mimetics are listed in Table 17.4. Table 17.4 Examples of the Amylin Analogs and Incretin Mimetics Incretin mimetics: Non-insulin antidiabetic drugs that act like the natural gut hormones (e.g., GLP-1) secreted in response to food in the stomach. They work with insulin to prevent blood glucose levels from becoming too high after meals. This results in an increase in insulin secretion, a decrease in glucagon secretion, and a slower rate of gastric emptying. DRUG/ADULT DOSAGE RANGE NURSING IMPLICATIONS albiglutide (Tanzeum) 30–50 mg subcutaneously once weekly (prefilled pen) • Assess for signs of an allergic reaction to the drug. dulaglutide (Trulicity) 0.75–1.5 mg subcutaneously once a week • Assess the patient for pancreatitis (i.e., abdominal pain, bloating, and exenatide (Byetta) 5–10 mcg subcutaneously every 12 hours within 60 minutes nausea) because this is a possible adverse effect of incretin mimetics. before meals • Assess the patient's blood sugar level before injecting the drug to exenatide extended-release (Bydureon) 2 mg subcutaneously once every 7 days prevent hypoglycemia. liraglutide (Victoza) 0.6 mg subcutaneously once daily for 7 days, then 1.2–1.8 • Teach the patient and family the correct procedure for preparing the mg once daily subcutaneously skin, injecting the drug with the pen injector, and proper disposal of lixisenatide (Adlyxin) Initial dose: (green pen 50 mcg/mL) 10 mcg needles and syringes to ensure best action and prevent complications. subcutaneously before first meal of the day; maintenance dose: (burgundy • Assess the patient for signs of thyroid cancer (i.e., lump in the throat pen 100 mcg/mL in 3 mL) 20 mcg subcutaneously 1 hour before the first meal or difficulty swallowing) because these drugs are associated with an of the day increased risk for the disease. • Instruct the patient to avoid alcohol because together alcohol and the incretin mimetics increase the risk for pancreatitis. Amylin analogs: Injectable non-insulin antidiabetic drugs that are similar to natural amylin, which is a hormone produced by pancreatic beta cells that works with and is co-secreted with insulin in response to blood glucose elevation. They prevent hyperglycemia by delaying gastric emptying and making the patient feel full so he or she eats less. DRUG/ADULT DOSAGE RANGE NURSING IMPLICATIONS pramlintide (Symlin) Initial dose: 15 mcg subcutaneously immediately before • Assess for signs of an allergic reaction to pramlintide. meals; maintenance: 30–60 mcg subcutaneously immediately before meals • Check blood sugar levels after meals because this is the drug's time of action and when hypoglycemia is most likely to occur. 585 • Monitor for symptoms of hypoglycemia. • Monitor the patient for the presence of dizziness, which is a possible side effect of this drug. • Teach the patient/family proper skin preparation and how to correctly inject the drug using the pen injector because drug effectiveness is related to correct administration of the drug. • Teach the patient/family to rotate the injection sites and proper disposal of the needles and syringes to prevent complications. • Instruct the patient to avoid alcohol because together alcohol and pramlintide increase the risk for pancreatitis. GLP-1, Glucagon-like peptide-1. Expected Side Effects Common side effects of the incretin mimetics include nausea, vomiting, diarrhea, and upper respiratory tract symptoms. Many patients lose weight when taking this drug. Adverse Effects Incretin mimetics can cause allergic reactions (hives, facial swelling, and trouble breathing). There are several long-term potential adverse effects. Pancreatitis can occur in people with DM who are obese. These drugs also appear to increase the risk for thyroid cancer. Drug Interactions Many herbal products or drugs interact with incretin mimetics. Ask the healthcare provider or pharmacist about potential interactions. Sulfonylureas increase the risk for hypoglycemia. Incretin mimetics slow the absorption of other drugs, including antibiotics and contraceptive drugs. Take other drugs 1 hour before incretin mimetics. Nursing Implications and Patient Teaching Planning and implementation. Assess the patient for signs of allergic reaction to the drug. Assess the patient for signs of abdominal pain, bloating, and nausea. Assess the patient's blood sugar level, especially after beginning this drug. Ensure that the patient and family understand and can demonstrate cleansing the skin, injecting the drug, rotation of injection sites, and proper disposal of the needles and syringes. Assess the patient for signs of thyroid cancer such as a lump in the throat or difficulty swallowing. Patient and family teaching. Tell the patient and family the following: • Report any signs or symptoms of allergic reaction to your healthcare provider. If you have difficulty breathing, a “lump” in your throat, or swelling of the mouth and tongue, call 911 or go to the nearest 586 emergency department immediately. • Avoid alcohol intake because it makes the risk for pancreatic inflammation worse when you are taking these drugs. • Monitor your blood sugar regularly, especially if you are taking more than one drug for your diabetes. • Seek immediate help for severe abdominal pain and nausea that can signal pancreatitis. • If a dose is accidentally missed, do not double up injections; simply take the missed dose as soon as possible. • Give the subcutaneous injection in the thigh, upper arm, or abdomen, rotating injection sites regularly. • Inject the drug 60 minutes before meals, not after meals. • Refrigerate unused injectable pens until they are used or expired. Dispose of them in a regulation sharps container. Memory Jogger Symptoms of Acute Pancreatitis • Severe upper abdominal pain that radiates to the back • Indigestion • Nausea and vomiting • Bloating with distended abdomen • Rapid heart rate Amylin Analogs Action and Uses Amylin analogs are a category of injectable non-insulin antidiabetic drugs that are similar to natural amylin, which is a hormone produced by pancreatic beta cells that works with and is secreted along with insulin in response to blood glucose elevation. The only drug currently in this class is pramlintide, which prevents hyperglycemia by delaying gastric emptying and making the patient feel full so he or she eats less. It is used for patients with DM type 1 and type 2. Patients with DM type 1 take this drug because people who do not secrete insulin are usually deficient in amylin. The 587 usual adult dosages and nursing implications for pramlintide are listed in Table 17.4. Expected Side Effects Nausea, vomiting, headache, abdominal pain, weight loss, and fatigue can occur with pramlintide. This drug can cause dizziness. Adverse Effects This drug can cause severe hypoglycemia, especially if used with insulin to treat diabetes. If it occurs, severe hypoglycemia will develop within 3 hours of injecting the drug. The drug is associated with pancreatitis. Drug Interactions Some drugs that can affect how pramlintide works include aspirin, atropine, disopyramide, fluoxetine, pentoxifylline, certain blood pressure and cholesterol drugs, and monoamine oxidase (MAO) inhibitors. Pramlintide interferes with the absorption of antibiotics and birth control pills, which should be taken at least 1 hour before pramlintide. Top Tip for Safety Teach patients to take prescribed antibiotics and oral contraceptives at least 1 hour before taking pramlintide because it interferes with the absorption of these other drugs. Nursing Implications and Patient Teaching Planning and implementation. Assess for signs of allergic reaction to pramlintide. Check blood sugar after meals to assess effectiveness of the drug and to screen for hypoglycemia. Monitor the patient for dizziness; if present, notify the healthcare provider because the dose may need adjustment. Ensure the patient and family understand and can demonstrate the process for drawing up the drug, cleansing the skin, injecting the drug, rotation of injection sites, and proper disposal of the needles and syringes. Patient and family teaching. Tell the patient and family the following: • This drug is injected into the thigh or stomach area, rotating the injection site regularly. • Opened vials and injectable pens should be kept refrigerated. If not refrigerated, they must be used within 28 days, then discarded. 588 • Allow the drug to warm to room temperature before injecting it. • Give this injectable drug right before your meal. • Never mix pramlintide with insulin in the same syringe. • Dispose of all used syringes and needles into a regulation sharps container. • If you miss a dose, and cannot take it within a reasonable time period, skip the dose. Do not double up on doses to make up for a missed dose. • Do not drink alcohol while taking pramlintide because the risk for pancreatitis increases if you drink alcohol while taking this drug. • Check your blood sugar regularly. Do not take pramlintide if your blood sugar is too low. • This drug can cause dizziness. Do not drive or operate machinery until you know how this drug affects you. • Report signs and symptoms of hypoglycemia to your healthcare provider. DPP-4 Inhibitors Action and Uses DPP-4 (dipeptidyl peptidase-4) inhibitors are a category of non-insulin antidiabetic drugs that help prevent hyperglycemia by reducing the amount of the enzyme DPP4, which inactivates the normal gut hormones (incretins), such as GLP (glucagon-like peptide) and GIP (gastric inhibitory polypeptide). These actions allow the naturally produced incretins to be present and work with insulin to control blood glucose levels. These drugs are approved for use only in patients who have DM type 2. The names, usual adult dosages, and nursing implications of the DPP-4 inhibitors are listed in Table 17.5. Table 17.5 Examples of DPP-4 Inhibitors and Sodium-Glucose Co-Transport Inhibitors DPP-4 inhibitors: Non-insulin antidiabetic drugs that help prevent hyperglycemia by reducing the amount of the enzyme (DPP-4), which inactivates the normal incretins, GLP and GIP. These actions allow the naturally produced incretins to be present and work with insulin to control blood glucose levels. DRUG/ADULT DOSAGE RANGE NURSING IMPLICATIONS alogliptin (Nesina) 25 mg orally once • Assess for signs of an allergic reaction or angioedema (swelling of the face, mouth, tongue, or larynx, often daily accompanied by hives). linagliptin (Tradjenta) 5 mg orally once • Check blood sugar regularly. daily • Monitor for signs and symptoms of hypoglycemia because if these drugs are taken with an insulin sensitizer saxagliptin (Onglyza) 2.5–5 mg orally or with insulin, the risk for hypoglycemia is increased. once daily • Assess for signs and symptoms of pancreatitis, which is a possible adverse reaction to these drugs. 589 sitagliptin (Januvia) 100 mg orally once daily Sodium-glucose co-transport inhibitors: Non-insulin antidiabetic drugs that lower blood glucose levels by preventing the kidney from reabsorbing glucose that was filtered from the blood into the urine. This glucose then remains in the urine and is excreted rather than moved back into the blood. DRUG/ADULT DOSAGE RANGE NURSING IMPLICATIONS canagliflozin (Invokana) 100 mg orally • Assess the patient for signs of an allergic reaction to sodium-glucose co-transport inhibitors. daily taken before the first meal of the • Assess the patient's blood sugar level. day • Assess the patient for signs and symptoms of hypoglycemia because the action of these drugs is to excrete dapagliflozin (Farxiga) 5–10 mg orally glucose in the urine. daily in the morning, with or without • Assess the patient for unintended weight loss, a symptom of dehydration, which is a complication of these food drugs. empagliflozin (Jardiance) 10-25 mg • Monitor the patient for symptoms of UTI (urgency, burning, painful urination, bloody or dark-colored urine, orally daily in the morning, taken with fever, chills, and back pain) because the increased concentration of glucose in the urine increases the risk for or without food urinary tract infection. • Monitor female patients for symptoms of vaginal infection (vaginal discharge with itching, redness, burning, and soreness), because the increased glucose in the urine predisposes patients to genitourinary tract fungal infections. • Assess the patient for signs of dehydration (e.g., increased thirst, dry mouth, decreased urine output, dizziness, and headache). • Monitor the patient's serum potassium level and for symptoms of hyperkalemia (e.g., muscle twitching, numbness and tingling, or irregular heart rate). GIP, Gastric inhibitory polypeptide; GLP-1, glucagon-like peptide-1; UTI, urinary tract infection. Expected Side Effects Nasopharyngitis, with cold-like symptoms of sneezing, runny nose, cough, and swelling of the nasal passages, can occur. Diarrhea has also been reported with the use of DPP-4 inhibitors. Adverse Effects Hypoglycemia can occur when given in combination with insulin or a sulfonylurea. Allergic reactions with symptoms of hives, facial swelling, and itching can occur. Reports of acute and even fatal pancreatitis have occurred with these drugs. It is unknown whether persons with a history of pancreatitis are at increased risk. Severe arthralgia (joint pain) has been reported in patients who are taking DPP-4 inhibitors. Bullous pemphigoid, a rare skin condition that results in large, fluid-filled blisters that most often occur in the lower abdomen, upper thighs, or armpits, has also been reported (Fig. 17.1). FIG. 17.1 Bullous pemphigoid. (From Habif TP: Clinical dermatology, ed 6, St. Louis, 2016, Elsevier.) Drug Interactions The effectiveness of DPP-4 inhibitors may be reduced when taken with erythromycin, ketoconazole, and other drugs that change the activity of 590 metabolizing enzymes. Consult a drug reference or a pharmacist to determine whether other drugs the patient is prescribed change the effectiveness of DPP-4 inhibitors. Nursing Implications and Patient Teaching Planning and implementation. Assess for signs of allergic reaction or angioedema (swelling of the face, mouth, tongue, or larynx, often accompanied by hives; see Fig. 8.10). If any of these indications appear, notify the healthcare provider immediately. Check blood sugar to assess the effectiveness of the drug and to screen for hypoglycemia, especially if the patient is taking insulin or a sulfonylurea. Patient and family teaching. Tell the patient and family the following: • Take the drug as ordered. If a dose is accidentally missed and cannot be taken within a reasonable time, do not double up on the drug dose. Take the next dose as scheduled. • Check your blood sugar regularly, report any hypoglycemia incidents to your healthcare provider. • Report symptoms of allergic reaction or angioedema associated with the drug to your healthcare provider. • Report symptoms of acute pancreatitis (e.g., upper abdominal pain radiating to the back, nausea and vomiting, fever, or rapid pulse) to your healthcare provider immediately. • Inform your healthcare provider if you become pregnant, because it is unknown whether these drugs are safe for use during pregnancy or when breast-feeding. • Tell your healthcare provider all of the drugs you are taking, because many drugs can interfere with the effectiveness of DPP-4 inhibitors. Safety Alert! Drug Interactions 591 • Many drugs used to treat diabetes interact with other drugs the patient may be taking. • Obtain a complete list of all drugs and supplements that the patient is taking. • Oral contraceptives and antibiotics can interact with drugs for diabetes, reducing their effectiveness. Sodium-Glucose Co-Transport Inhibitors Action and Uses Sodium-glucose co-transport inhibitors are a new category of non-insulin antidiabetic drugs that lower blood glucose levels by preventing the kidney from reabsorbing glucose that was filtered from the blood into the urine. This glucose then remains in the urine and is excreted rather than moved back into the blood. These drugs are approved for use only in patients who have DM type 2. The names, usual adult dosages, and nursing implications of sodium-glucose co-transport inhibitors are listed in Table 17.5. Expected Side Effects An increased need to urinate has been reported in patients who are taking sodiumglucose co-transport inhibitors. Patients who are using glucose strips to check for glucose in the urine will see a positive result most of the time because glucose is excreted in the urine. Weight loss initially through the loss of fluid followed by loss of fat mass can occur. Adverse Effects Vaginal yeast infections and urinary tract infections (UTIs) are the most commonly reported problems, with the greatest risk being in female patients and uncircumcised men. Kidney failure, hyperkalemia (high level of potassium in the blood), ketoacidosis, increased risk for bladder cancer, and hypotension (low blood pressure) are other potential serious adverse effects. Also allergic reactions, hypoglycemia, and dehydration can occur. Drug Interactions Combining sodium-glucose co-transport inhibitors with insulin increases the likelihood for hypoglycemia. When these drugs are given with diuretics, the frequency of urination increases and can result in dehydration. Some drugs such as rifampin, phenytoin, ritonavir, and phenobarbital decrease the efficacy of sodiumglucose co-transport inhibitors, requiring an increased dose. Nursing Implications and Patient Teaching Planning and implementation. Assess the patient for signs of allergic reaction to sodium-glucose co-transport inhibitors. Assess the patient's blood sugar level to check for hypoglycemia. Check the patient's weight at the start of therapy, and at regular intervals, as these 592 drugs can cause weight loss. Monitor the patient for symptoms of urinary tract infection (UTI): urgency, burning, painful urination, bloody or dark-colored urine, fever, chills, and back pain. Monitor female patients for symptoms of vaginal infection (vaginal discharge with itching, redness, burning, and soreness). Assess the patient for signs of dehydration (increased thirst, dry mouth, decreased urine output, dizziness, and headache). Monitor the patient's serum potassium level and for symptoms of hyperkalemia (muscle twitching, numbness and tingling, and irregular heart rate). Patient and family teaching. Tell the patient and family the following: • Notify your healthcare provider if you have any symptoms of an allergic reaction to the drug. • Check your blood sugar at regular intervals. • Weigh yourself at least once a week and report any undue or unexpected weight loss. • Report any signs of a UTI or vaginal infection to your healthcare provider. • Make sure you are drinking enough fluids throughout the day to prevent dehydration. • You will see the presence of glucose in your urine if you test your urine with a glucose test strip. This is to be expected because the drug works by excreting glucose into the urine for elimination. Insulin Action and Uses The pancreas is responsible for making insulin and glucagon, both of which work to maintain blood glucose levels. Insulin is made by the beta cells of the pancreas. When levels of glucose are abnormally elevated in the blood, this is known as hyperglycemia. When blood sugar levels become elevated, insulin is released from the beta cells of the pancreas to help restore normal blood sugar levels by moving insulin into cells and allowing insulin to bind to insulin receptors on the cell membrane (Fig. 17.2). A fasting glucose level of 70 to 90 mg/dL is considered normal. 593 FIG. 17.2 Action of insulin. (From Workman ML, LaCharity LA: Understanding pharmacology, ed 2, St. Louis, 2016, Elsevier.) Once insulin binds to the insulin receptor, a series of reactions take place in the cell, making it easier for glucose to pass into the cell. In addition to its role in glucose control, insulin is also very important in fat metabolism. Adequate amounts of insulin inhibit the release of fatty acids into the blood, thus preventing high blood lipid levels. Insulin is an anabolic hormone (one that converts simple substances into more complex compounds) that helps maintain stores of fatty acids, glycogen, and protein. Insulin is considered a high-alert drug. Top Tip for Safety High-Alert Drug • Insulin is a high-alert drug that can cause great harm when given at too high a dose, too low a dose, not given to a patient for whom it was prescribed, or given to someone who does not have diabetes. • If insulin is given to a patient without diabetes, or if given at a high dose, the patient can become severely hypoglycemic, which can result in death. • If insulin is given at too low a dose, a patient's blood glucose level is poorly controlled, increasing the risk for severe hyperglycemia, ketoacidosis, and even death. • Older patients with poor vision may benefit from prefilled insulin syringes, cartridges, or pens to prevent dosing errors. 594 Recent recommendations for glucose control in DM type 1 consist of multiple-dose insulin injections (three to four injections per day), known as intensive insulin therapy, or by continuous subcutaneous insulin infusion via an insulin pump (Fig. 17.3). Insulin must be given by the parenteral route because it is destroyed by stomach acids and intestinal enzymes. At present, most patients use specific insulin syringes with a small, thin needle designed specifically for insulin dosage (in units) and subcutaneous injection into the thigh, upper arm, or abdomen (Fig. 17.4). Various injection devices have also been developed to simplify insulin injection. Some of these look like a pen, and patients just have to dial the insulin dosage needed and touch the tip to their skin where the insulin is automatically injected (Figs. 17.5 and 17.6). These products do not need to be refrigerated, so they can easily be carried by the patient. Internal or external insulin pumps are computer driven and can be programmed to release small doses of insulin continuously as needed, or hourly. FIG. 17.3 Insulin pump. (A) MiniMed 670G System. (B) MiniMed system in use on a patient. (Courtesy Medtronic MiniMed, Inc.) 595 FIG. 17.4 U-100 and U-50 syringes. (From Workman ML, LaCharity LA: Understanding pharmacology, ed 2, St. Louis, 2016, Elsevier.) FIG. 17.5 Injection pen for the incretin mimetic Byetta. (Courtesy Eli Lilly & Company, Indianapolis, IN, and Amylin Pharmaceuticals, San Diego, CA.) FIG. 17.6 Example of an insulin pen injector. (Courtesy Novo Nordisk Inc.) 596 Each patient with DM who needs insulin therapy will be placed on an insulin regimen, which is the schedule of insulin aimed at preventing hyperglycemia. The dose of insulin and how often it is to be given or taken varies between patients. Generally, patients are scheduled to receive a long-acting insulin in the morning, with short-acting insulin given to cover meals and snacks. Whenever short-acting insulin is given before a meal, the patient will need to eat the meal within 15 minutes of receiving the injection to prevent hypog