Chapter 32- Antidiabetic Drugs Flashcards
Diabetes Mellitus
A complex disorder of carbohydrate, fat, and protein metabolism resulting primarily from the lack of insulin secretion by the B-cells of the pancreas or from defects in the insulin receptors. There are type 1 and type 2 diabetes.
Diabetic ketoacidosis (DKA)
Severe metabolic complication of uncontrolled diabetes, which,if untreated, leads to diabetic coma and death.
Gestational diabetes
Diabetes that develops during pregnancy. May resolve after pregnancy but may also be a precursor of type 2 diabetes.
Insulin must be given to prevent birth defects.
Glucagon
Hormone produced by the a-cells in the islets of Langerhans that stimulates the conversion of glycogen to glucose in the liver
Glucose
A simple sugar that serves as a major source of energy
Glycogenolysis
The breakdown of glycogen to glucose
Hemoglobin A1C (HbA1c)
Hemoglobin molecules to which glucose molecules are bound; blood levels of hemoglobin A1C are used as a diagnostic measurement of average daily blood glucose in the monitoring of diabetics
Hyperglycemia
A fasting blood glucose level of 7mmol/L or higher or a non fasting blood glucose level of 11.1mmol/L or higher
Hyperosmolar nonketotic syndrome (HNKS)
A metabolic complication of uncontrolled diabetes, similar in severity to DKA but without ketosis and acidosis.
Hypoglycemia
Blood glucose level less than 2.8mmol/L.
Mild cases treated with diet.
Early symptoms: confusion, irritability, tremor, sweating. Later symptoms: Hypothermia, seizures, coma and death will occur if not treated.
Imparied fasting glucose level
A pre diabetic state defined as a fasting glucose level of at least 6.1mmol/L but lower than 6.9mmol/L; prediabetes
Insulin
A naturally occurring hormone secreted by the B-cells of the islets of Langerhans in the pancreas in response to increased levels of glucose in the blood.
Ketones
Organic chemical compounds produced through the oxidation of secondary alcohols (fat molecules) including dietary carbohydrates
Polydipsia
Chronic excessive intake of water; it is a common symptom of diabetes
Polyphagia
Excessive eating; common symptom of diabetes
Polyuria
Increased frequency or volume of urinary output; common symptom of diabetes
Type 1 diabetes mellitus
Genetically determined autoimmune disorder involving a complete or nearly complete lack of insulin production; most commonly develops in children or adolescents.
Type 2 diabetes mellitus
Most commonly presents in middle age. Disease may be controlled by lifestyle modifications, oral drug therapy, insulin, or a combination of these measures, but patients are not necessarily dependent on insulin.
Long term complications of Diabetes
Macrovascular: atherosclerotic plaque. Coronary arteries, cerebral arteries, peripheral vessels.
Microvascular: capillary damage. Retinopathy, neuropathy, nephropathy (kidney damage)
Acute complications of Diabetes
Diabetic ketoacidosis- Life Threatening!: Extreme hyperglycaemia, presence of ketones in serum, acidosis, dehydration, electrolyte imbalances.
Hypersmolar nonketotic syndrome: Triggered by extreme hyperglycaemia, precipitated by physical or emotional stress. Treated with IV fluids and electrolyte replacement, Insulin therapy.
Insulins
Substitute for endogenous hormone and has same effects as normal endogenous insulin.
Restore the diabetics patients ability to metabolize carbs, fats and proteins. Store glucose in the liver and convert glycogen to fat storage
Most now use recombinant DNA technologies
Aim to reduce the incidence of long-term complications
Rapid Acting insulins
10-15 minutes. Shorter duration. Given SubQ or infusion pump but not IV.
Ex) Insulin aspart (NovoRapid), insulin lispro (Humalog)
Short Acting Insulins
Onset 30-60 minutes. Ex) Regular insulin (Humulin R)-only one given IV and (Toronto)
Intermediate Acting Insulin
NPH (Humulin-N)
Cloudy appearance. Slower in onset and more prolonged duration
Long acting insulin
Insulin glargine (Lantus), Insulin detemir (Levemir)
Combination insulin products
Regular insulin 30% (short acting) and NPH 70% (long acting) - Humulin 30/70; Novolin ge 30/70
Sliding scale insulin dosing
SubQ short acting or regular insulin doses are adjusted according to blood glucose test results.
Typically use in hospitalized diabetic PTs on total parenteral nutrition or enteral tube feedings.
Done before breakfast, lunch, and supper
Oral Antidiabetic drugs
Used for type 2 diabetes. May not be effective unless PT is making lifestyle and behavioural changes.
Ex) Sulfonylureas: gliclazide (Diamicron), glyburide (Dibeta)
Meglitinides: repaglinide (GlucoNorm)
Biguanides: metformin (Glucophage)
Thiazolidinediones aka glitazones: rosiglitazone (Avandia)
a-Glucosidase inhibitors: acarbose (Glucobay)
Oral Antidiabetic Mech of Action
Sulfonylureas: Stimulate insulin secretion from pancreas. Improve sensitivity to insulin in tissues. Lower blood glucose levels.
Meglitinides: Similar to sulfonylureas. Increase insulin secretion from pancreas
Biguanides: Decrease production of glucose. Increase uptake of glucose. Do not cause hypoglycemia.
Thiazolidinediones: Decrease insulin resistance, increase glucose uptake.
a-Glucosidase inhibitors: Must be taken with meals to prevent after meal (postprandial) blood glucose elevations. Take with first bit of a meal.
Oral Antidiabetic Indications
Used alone or in combination with other drugs, diet and lifestyle changes.
Oral Antidiabetic Contraindications
Active hypoglycemia
Oral Antidiabetic Adverse Effects
Sulfonylureas: Nausea, heartburn.
Meglitindies: Headache, hypoglycemic
Metformin: Metallic taste, lactic acidosis, does not cause hypoglycemia
Thiazolidinediones: moderate weight gain, edema, mild anemia, hepatic toxicity.
a-Glucosidase inhibitors: flatulence, diarrhea, abdo pain, do not cause hypoglycaemia or weight gain
Oral Antidiabetic Interactions
Sulfonylureas: Hypoglycemic effect increases when taken with alcohol, anabolic steroids, and many others. Allergic cross-sensitivity may occur with loop diuretics and sulphonamide antibiotics.
Glucose-Elevating Drugs
50% dextrose in water (D50W) IV. Glucagon
Nursing Implications
Concerns increase when PT is: stressed, has an infection, illness or trauma, or is pregnant or lactating.
Insulin: Check blood glucose levels before giving insulin. Roll vials. Store in fridge for 3 months. Store in room temp for 1 month. Ensure correct timing with meals. When drawing up two types of insulin in one syringe, always withdraw the regular or rapid first. Rotate injection sites.
Oral antidiabetic drugs: Always check glucose levels before giving. Give 30 mins before meals. Metformin is taken with meals to reduce GI effects. Stop metformin 48hrs prior to a CT.
Assess for hypoglycemia. If occurs, give glucagon, glucose tablets, or have pt eat a small snack with protein and a carb.
Monitor blood glucose levels.
Monitor for Therapeutic effects: decrease in blood glucose levels. measure hemoglobin A1c.
