Ch. 57: Antidiabetics Flashcards
Symptoms of Diabetes Mellitus
- polyuria, polydipsia, polyphagia, unexplained weight loss, fatigue, hyperglycemia
Hyperglycemia
- high BG levels
- Dx: symptoms or BG measurments
- symptoms: extreme thirst, need to urinate often, dry skin, hungry, blurry vision, drowsy, slow healing of wounds
- Tx: insulin or oral antidiabetic agent `
Criteria for DM Diagnosis
- symptoms of diabietes plus casual plasma glucose level more or equal to 11.1 mmol/L OR
- fasting plasma glucose higher than or equal to 7 mmol/L OR
- oral glucose tolerance test: 2 hour postload glucose level higher than or equal to 11.1mmol/L during test
Treatment for Diabetes Mellitus
type 1:
- glycemic control with diet, physical activity, ect. and insulin replacement therapy
type 2:
- lifestyle changes, oral drug therapy and insluin when the above no longer provide glycemic control
Antidiabetic Agents: aim to produce normal blood glucose states
Insulin
- all given subQ, sometimes IV but never PO
- mainly used in type 1
- insulin analogs: modified forms of human insulin with same action but different time courses
- contradicitions: drug allergy or HYPOGLYCEMIA
- adverse: hypoglycemia, tachycardia, headache, delirium, tremors, hunger, dry mouth, sweating, and hunger; hypokalemiia and lipohypertophy
- most serious: shock and death from untreated hypoglycemis
Human-Based Insulins: Rapid-Acting
- 10-15mins, shorter duration of action
- aspart, lispro, and glulisine
- must be given subQ (not IV)
Human-Based Insulins: Short-acting
- like naturally produced insulin
- onset 30-60mins
- only product that can be given by IV bolus, IV infusion, or even IM
- Humulun-R, Novolin
Human-Based Insulins: Intermediate-acting
- isophane, also called NPH
- has cloudy appearance
- slower onset and more prolonged duration than endogenous insulin
Human-Based Insulins: Long-acting
- insulin glargine (clear and colourless)
- insulin detemir (clear and colourless)
Insulin Interactions
- furosemide, sympathomimetics, glucocorticoids, thiazides, and thyroid hormones = antagonize hypoglycemic effects = hyperglycemia
- alcohol, other hypoglycemic agents, ACE inhibitors, MAOIs, salicylates = increase hypoglycemia effects = hypoglycemia
- beta-blockers can mask effects of hypoglycemia and prevent body’s normal response
Storage
- ref unopened vials (do not freeze)
- after opening can be kept up to one month
- avoid sunlight and extreme heat
- stable
Oral Antidiabetic Agents
- type 2 in addition to lifestyle mod
- may not be effective unless patient also makes behavioural or lifestyle change
Biguanides
- decrease glucose production by liver and intestinal absorption
- improve insulin receptor sensitivity; increase uptake of glucose by tissues and does not increase insulin secretion from pancreas
- common agent: metformin (Glucophage)
Metformin (Glucophage)
adverse: affects GI tract: decrease appetite, ab bloating, nausea, cramping, diarrhea, feeling full
- cause metaliic taste, reduced vit B12 and folic acid levels = peripheral neuropathy
- cause lactic acidosis if toxic
- does not cause hypoglycemia
interactions: alcohol: inhibits lactic acid breakdown = toxicity
- cimetidine and furosemide = increased metformin concentration
- digoxin = increased metformin concentration
- radiological contract medium = kidney failure
Sulfonylureas
- 1st gen drug not used as frequently now; 2nd generation more potent and less interactions
2nd gen: gliclazide and glyburide - stimulate insulin secretion from pancreatic beta cells = increased transport glucose out of blood and into tissues; improve sensitivity of insulin receptor proteins in cells to insulin in tissues = lower blood glucose levels
- adverse: hypoglycemia, weight gain, hematological effects, nausea, epigastric fullness, heartburn; CV toxicity; do not use in prego
- interactions: hypoglycemic effect increases with alcohol, NSAIDs, sulfa antibiotics; adrenergics, steroids, thiazides reduce hypoglycemic effect
Repaglinide (GlucoNorm)
- meglitinides
- have action similar to that of sulonylureas
- block ATP-sensitive K+ channels on pancreatic beta cells = calcium influx = increase insluin release
- adverse: headache, hypoglycemic effect, angina, chest pain, weight gain, slowed metabolism in clients with decrease liver fx
- interactions: NSAIDs, sulfonamides = increased hypoglycemic effect
- thyroid med, thiazide diuretics = decreases hypoglycemic effects
Acarbose (Glucobay)
- alpha-glucosidase inhibitor
- reversibily inhibit a-glucosidase enzyme in small intestine = delayed carb absorption
- MUST be taken with meals (first bite)
- adverse: GI: flatulence, diarrhea ,ab pain; elvate liver enxymes; do not cause hypoglycemia, or weight gain
- interactions: loop/diuretics, corticosteroids, thyroid replacement, digoxin, sympathomimetics = hyperglycemia
- contradictions: allergy, active hypoglycemia, severe liver/kidney disease; do not use in prego
Hypoglycemia
- abnormally low blood glucose level (below 2.8mmol/L)
- symptoms: early (confusion, irritability, termor, sweating); later (hypothermia, seizures, coma or death)
Glucagon (glucaGen)
- raises blood glucose levels
- polypeptide hormone that is produced normally in body by alpha cells
- absorbed rapidly IM, subQ, IV
- liver to break down glycogen to glucose which body can use
- used in emerg treatment of severe hypoglycemia
- interactions: anticoagulants
Antidiabetic Agents: Nursing Implications
- client assess
- blood glucose levels
- type, dose, and timing?
- allergies
- signs and symptoms of hypo and hyperglycemia
- make sure client eats
- FACILITY POLICY
- concerns increase when: under stress, has an infection, has an illness or trauma, is prego or lactating
- assess for signs of hypoglycemia: give glucagon if there or have patient eat glucose tablets or have patient eat a small snack
Nursing Implications: Insulin
- check levels before giving insulin
- roll vials between hands to mix suspensions instead of shaking them
- ensure correct storage of insulin vials
- ONLY syringes are to be used to measure and admin
- ensure timing within meals
- always withdraw rapid-acting insulin first
- patient eduction
Nursing Implications: Oral Antidiabetic Drug
- ALWAYS check blood glucose levels before giving
- give 30 mins before meals
- metformin is taken with meals to reduce GI effects
