Endocrine 1, 2 Flashcards
Insulin MOA
Insulin binds to plasma membrane receptors initiating an intracellular cascade of enzymatic events: Glucose diffusion into cells, glucose storage mode, uptake of AA/phos/K/mg, protein synthesis, inhibition of proteolysis, fatty acid/TG synthesis, dec lipolysis, regulate DNA/ gene expression (via insulin regulatory elements)
___ units of physiologic insulin is the average daily requirement
40 units
In what way does ANS control insulin release?
Alpha decreases insulin secretion
Beta and PSNS increases insulin secretion
Which insulins are mixed commonly?
R/NPH or rapid/NPH
Before breakfast, R covers breakfast, NPH covers lunch (or R dinner; NPH night)
Which types of insulin are ultra-rapid acting? Onset, peak, DOA?
Lispro (humalog)
Aspart (novolog)
Glulisine (apidra)
Onset 15-30 min, peak 30-60 min, DOA 3-5h
Which types of insulin are short acting? Onset? Peak? DOA?
Regular (humulin R, novolin R)
Onset 30 min (slight peak of glucose before insulin starts working)
Peak 1-5h, DOA 5-8h
Which types of insulin are intermediate acting? Onset? Peak? DOA?
NPH (humulin N, novolin N)
P=protamine (this is what we use to reverse heparin), they may develop protamine allergy over time
Onset 1-2h, peak 6-10h, DOA 16-20h
Which types of insulin are long-acting? Onset, peak, DOA?
Glargine (lantus)- no peak, not mixed with other insulins Detemir (levemir) Ultralente Stimulate basal release (no peak) Onset 2-6h, DOA 24h
IV regular insulin pharmacokinetics? E1/2t, DOA, metabolism
E1/2t 5-10 min
DOA 30-60 min
Proteolytic enzyme metabolizes insulin in the liver and kidneys
Insulin adverse reactions?
HYPOGLYCEMIA Injection site reaction Lipodystrophy at site Protamine allergy (only NPH) Weight gain
Hypoglycemia symptoms?
Diaphoresis, tachycardia, hypertension (epi response to raise BG), CNS agitation, seizures, coma
Drug interactions with insulin?
ACTH, glucagon, estrogens- oppose hypoglycemic effects
Epi decreases release of insulin (raises BG)
Tetracycline, chloramphenicol, salicylates- prolong DOA
MAOIs increase hypoglycemic effects
In type 1 DM, 1 unit insulin decreases BG by ____
In type 2 DM 1 unit insulin decreases BG by ____
Type 1: 40-50 mg/dL
Type 2: 30-40 mg/dL
Although it varies with individuals
Benefits of tight controlled BG vs. non-tight control?
Tight control: reduces risk of chronic complications in type 1 DM, also inc wound healing, dec infection, dec osmotic diuresis, dec DKA incidence
Non-tight control: when controlled to tightly, we risk hypotension, plus its annoying and more work
Hyperkalemia treatment
10u Reg insulin IV
25g glucose, 1 amp 50% dextrose in 5 min
Hypoglycemia treatment
OJ, soda, honey, sugar tablet/cube
25-50 mL 50% dextrose solution
Which of these oral antidiabetic medications cause hypoglycemia?
Sulfonylureas, biguanides, thiazolidinediones, alpha-glucosidase inhibitors, melitinides, GLP-1 mimetics/gliptons
Can cause hypoglycemia: Sulfonylureas, gliptons, and meglitinides all increase insulin secretion from B cells
Don’t cause hypoglycemia: biguanides and TZDs increase insulin sensitivity at target tissues, alpha-glucosidase inhibitors slow absorption from the gut
Sulfonylureas MOA?
Stimulate release of insulin from pancreatic beta cells
Binds to ATP sensitive K channes in the cell membrane resultinmg in depolarization, Ca influx, and insulin release (tricks the beta cell into thinking it is in a glucose-rich state)
Secondary MOA: enhance beta cell sensitivity to glucose, enhance tissue sensitivity to insulin, lower BG
Sulfonylureas effect on FBG and Hbg A1C?
Reduce FBG 60-70 mg/dL
Reduce Hgb A1C 2%
List 1st and 2nd generation sulfonylreas and their DOA
1st: Tolbutamine (orinase) DOA 6-12h; chlorpropamide (diabinese) DOA 36-72h
2nd: glipizide (glucotrol) DOA 12-24h; glymuride (micronase, diabeta) DOA 18-24h; glimepiride (amaryl)
1st gen has more drug interactions and SE than 2nd bc 2nd gen is 100x more potent
Sulfonylureas pharmacokinetics?
90-98% protein bound
Metabolized hepatically (avoid in liver dz), some active metabolizes
If renal impairment, use glipizide or tolbutamide
Sulfonylureas adverse effects?
HYPOGLYCEMIA (hold 1-2 days preop)
GI: N/V, fullness, heartburn, cholestasis, altered LFTs, appetite stimulant (exacerbate obesity)
GU: ADH effect- Na and H2O retention
Pruritis, rash
Biguanides: MOA
metformin
Dec hepatic and renal glucose production (decreased gluconeogenesis/glycogenolysis), inhibits aerobic metabolism
Biguanides benefits
No weight gain, possible weight loss
May increase HDL, decrease LDLs and TGs
Hypoglycemia rare when used alone
Biguanides adverse effects
GI distress (diarrhea, metallic taste, nausea)
Lactic Acidosis
Rash
Hold 1-2 days before surgery
Biguanides contraindications
Women with ESRD, creatinine over 1.4
Med with ESRD, creatinine over 1.5
Hepatic dysfunction
CHF, shock, hypoxic pulmonary disease
Thiazolidinediones (TZDs): MOA, and name a couple?
Improves insulin sensitivity/decreases insulin resistance peripherally
Pioglitazone (Actos)
Rosiglitazone (Avandia)
TZDs clinical effect and pharmacokinetics?
Effect: decreases FPG up to 50 mg/dL, decreases Hgb A1C 1-2%, resumes ovulation in premenopausal women who have insulin resistance
PO, hepatic metabolism
Alpha-gucosidase inhibitors MOA and name a couple of them
MOA: competitively and reversibly antagonizes enzymes in the intestinal brush border responsible for digesting complex carbohydrates (when in the GI tract, it doesn’t get reabsorbed to the blood) delays glucose absorption, lowers post-prandial hyperglycemia (after a meal)
Acarbose (precose)
Miglitol (glyset)
TZD side effects and black box warning?
SE: edema, weight gain, hepatotoxicity (monitor LFTs, look for jaundice)
Black ox warning: CHF (can cause or exacerbate), MI (from rosiglitazone)
Alpha-glucosidase inhibitors clinical effect and pharmacokinetics?
Decreases PPG 60-70
Decreases FBG 25-30 only
Decreases Hbg A1C 0.7-0.9%
Not absorbed after oral administration, excreted in stool
Alpha-glucosidase inhibitors adverse effects? Cautions?
Abdominal pain/distention, diarrhea, flatulence
Caution in patients with IBD, ulcers, intestinal obstruction
Tak with first bite of meal, if you skip a meal, skip the dose
Meglitinides MOA, how do they compare to sulfonylureas?
MOA: stimulates insulin secretion from pancreatic beta cells, quick onset and peak (1h), short DOA (4h), reduces PPH (postprandial hyperglycemia)
Compared to sulfonylureas, less hypoglycemia, shorter DOA, quicker onset
Name a couple meglitinides, what are adverse effects?
Repaglinide (prandin), nateglinide (starlix)
AE similar to sulfonylureas, hypoglycemia, n/v/c/d, heartburn, headache
Take it 15-30 min before meals, if a meal is skipped, skip the dose