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
