Chapter 57
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Chapter 57. Drugs for Diabetes Mellitus. Diabetes Mellitus: Overview of the Disease and Its Treatment. Diabetes mellitus Greek word for “fountain” Latin word for “honey” Disorder of carbohydrate metabolism Deficiency of insulin Resistance to action of insulin
Chapter 57
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Presentation Transcript
Chapter 57 Drugs for Diabetes Mellitus
Diabetes Mellitus: Overview of the Disease and Its Treatment • Diabetes mellitus • Greek word for “fountain” • Latin word for “honey” • Disorder of carbohydrate metabolism • Deficiency of insulin • Resistance to action of insulin • Sustained hyperglycemia, polyuria, polydipsia, ketonuria, and weight loss
Types of Diabetes Mellitus • Type 1 diabetes • 5%–10% of all cases • Also called insulin-dependent diabetes mellitus (IDDM) or juvenile-onset diabetes mellitus • Primary defect is destruction of pancreatic beta cells
Types of Diabetes Mellitus • Type 2 diabetes • Most prevalent form of diabetes • Approximately 22 million Americans have it • Also called non–insulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes mellitus • Insulin resistance and impaired insulin secretion
Complications of Diabetes • Short-term • Hyperglycemia and hypoglycemia • Long-term • Macrovascular damage • Heart disease • Hypertension • Stroke • Hyperglycemia • Altered lipid metabolism
Complications of Diabetes • Long-term (cont’d) • Microvascular damage • Retinopathy • Nephropathy • Neuropathy • Gastroparesis • Amputation secondary to infection
Diabetes and Pregnancy • Before insulin: many babies born to severely diabetic women died • Factors during pregnancy • Placenta produces hormones that antagonize the actions of insulin • Production of cortisol increases threefold • Glucose can pass freely from the maternal to the fetal circulation (fetal hyperinsulinemia)
Diabetes and Pregnancy • Proper glucose levels needed in pregnant patient and in fetus to prevent teratogenic effects • Fetal death frequently occurs near term • Earlier delivery is desirable • Gestational diabetes
Diagnosis of Diabetes • Excessive plasma glucose is diagnostic of diabetes • Patient must be tested on two separate days, and both tests must be positive • Three tests • Fasting plasma glucose (FPG) • Casual plasma glucose • Oral glucose tolerance test (OGTT) • Hemoglobin A1c, oral glucose tolerance test
Prediabetes • Impaired fasting plasma glucose between 100 and 125 mg/dL • Impaired glucose tolerance test • Increased risk for developing type 2 diabetes • May reduce risk with diet changes and exercise and possibly with certain oral antidiabeticdrugs • Many people who meet criteria for “prediabetes” never develop diabetes, even if they do not take precautions against diabetes
Overview of Diabetes Treatment • Primary goal is to prevent long-term complications • Tight control of blood glucose level is important • Also important to control blood pressure and blood lipids
Type 1 Diabetes • Requires comprehensive plan • Integrated program of diet, self-monitoring of blood glucose, exercise, and insulin replacement • Dietary measures • Total number of carbohydrates, not the type of carbohydrates, is most important • Glycemic index
Type 2 Diabetes • Similar to type 1, requires comprehensive plan • Should be screened and treated for: • Hypertension, nephropathy, retinopathy, neuropathy, dyslipidemias • Glycemic control with: • Modified diet and exercise • Drug therapy
Monitoring Treatment • Self-monitoring of blood glucose (SMBG) • Hemoglobin A1c
Insulin: Physiology • Biosynthesis • Secretion • Metabolic actions • Metabolic consequences of insulin deficiency
Seven Types of Insulin • Short duration: rapid acting • Insulin lispro (Humalog) • Insulin aspart (NovoLog) • Insulin glulisine (Apidra) • Short duration: slower acting • Regular insulin (Humulin R, Novolin R) • Intermediate duration • Neutral protamine Hagedorn (NPH) insulin • Insulin detemir (Levemir) • Long duration • Insulin glargine
Insulin • Concentration • 100 units/mL (U-100) • 500 units/mL (U-500) • Mixing insulins • NPH with short-acting insulins • Short-acting insulin drawn first
Administration • Subcutaneous injection • Syringe and needle • Pen injectors • Jet injectors • Subcutaneous infusion • Portable insulin pumps • Implantable insulin pumps (experimental) • Intravenous infusion
Storage • Unopened vials should be stored under refrigeration until needed • Should not be frozen • Can be used until expiration date if kept in refrigerator • After opening, can be kept up to 1 month without significant loss of activity • Keep out of direct sunlight and extreme heat
Storage • Mixtures of insulin in vials are stable for 1 month at room temperature and for 3 months under refrigeration • Mixtures in pre-filled syringes should be stored in refrigerator for at least 1 week and should be stored vertically with needle pointing up
Insulin: Therapeutic Use • Indications • Principal: diabetes mellitus • Required by all type 1 and some type 2 patients • IV insulin for DKA • Hyperkalemia: can promote uptake of potassium • Aids in the diagnosis of GH deficiency
Insulin Therapy of Diabetes • Dosage • Dosing schedules • Conventional therapy • Intensive conventional therapy • Continuous subQ infusion • Achieving tight glucose control
Complications of Insulin Treatment • Hypoglycemia • Lipohypertrophy • Allergic reactions • Hypokalemia • Drug interactions • Hypoglycemic agents • Hyperglycemic agents • Beta-adrenergic blocking agents
Oral Hypoglycemics • Biguanides • Metformin (Glucophage) • Sulfonylureas • Thiazolidinediones(glitazones) • Rosiglitazone (Avandia) • Pioglitazone (Actos) • Meglitinides (Glinides) • Repaglinide (Prandin) • Nateglinide (Starlix)
Oral Hypoglycemics • Alpha-glucosidase inhibitors • Acarbose (Precose) • Miglitol (Glyset) • Gliptins • Combination products
Combination Products • Metformin/Glyburide • Metformin/Glipizide • Metformin/Saxagliptin • Metformin/Pioglitazone • Metformin/Repaglinide • Metformin/Sitagliptin • Pioglitazone/Glimepiride • Rosiglitazone/Glimepiride • Rosiglitazone/Metformin • Sitagliptin/Simvastatin
Injected Drugs (Other than Insulin) • Exenatide • Adjunctive therapy to improve glycemic control in patients with type 2 diabetes • Adverse effects • Hypoglycemia • Gastrointestinal effects • Liraglutide • Pramlintide
Acute Complications of Poor Glycemic Control • Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmotic nonketotic syndrome (HHNS): Both conditions are hyperglycemic crises • Hyperglycemia is more severe in HHNS • No ketoacidosis in HHNS
Diabetic Ketoacidosis • Severe manifestation of insulin deficiency • Symptoms evolve quickly in a period of hours or days • Most common complication in pediatric patients and leading cause of death • Characteristics • Hyperglycemia • Ketoacids • Hemoconcentration • Acidosis • Coma
Diabetic Ketoacidosis • Altered glucose metabolism • Hyperglycemia • Water loss • Hemoconcentration • Altered fat metabolism • Production of ketoacids
Diabetic Ketoacidosis • Treatment • Insulin replacement • Bicarbonate for acidosis • Water and sodium replacement • Potassium replacement • Normalization of glucose levels
HHNS • Large amount of glucose excreted in urine • Dehydration and loss of blood volume • Increases the blood concentrations of electrolytes and nonelectrolytes (particularly glucose); also increases hematocrit • Blood “thickens” and becomes sluggish
HHNS • Little or no change in ketoacid levels • Little or no change in blood pH • No sweet or acetone-like smell to urine or breath • HHNS occurs most frequently with type 2 diabetes mellitus with acute infection, acute illness, or some other stress
HHNS • Can evolve slowly • Metabolic changes begin a month or two before signs and symptoms become apparent • If untreated, HHNS can lead to coma, seizures, and death • Management • Correct hyperglycemia and dehydration with IV insulin, fluids, and electrolytes
Glucagon for Insulin Overdose • Preferred treatment is IV glucose • Immediately raises blood glucose level • Glucagon can be used if IV glucose is not available • Delayed elevation of blood glucose • Will not work in starvation • Promotes glycogen breakdown and the malnourished have little glycogen left