Endocrine Flashcards
What are 5 drugs that impact the endocrine system?
Bisphosphonates
Hypothalamic and pituitary hormones
Exocrine pancreatic enzymes
Antidiabetic agents
Thyroid and antithyroid agents
Pancreatic Enzyme Uses
Cystic fibrosis and pancreatitis
Some bariatric procedures require supplements
Pancreatic Enzyme Pharmacodynamics
Inactivated by ph values less than 4; do not crush or chew. Sprinkle on food if powdered form. Take immediately before or with meal.
Pancreatic Enzyme Pharmacokinetics
Absorption: none, acts locally in GI tract.
Excretion: feces
Pancrelipase made from pork; pancreatin made from pork, beef, or vegatable sources.
Precautions: antacids decrease effectiveness, decreases absorption of oral iron.
Pancreatic Enzymes: ADR and Drug Selection
Skin irritation, rashes, stomatitis, nausea
High doses: hyperuricosuria, hyperuricemia
Watch products because they are NOT bioequivalent. Most old formulas are no longer FDA approved.
Pancreatic Enzyme Monitoring
Pancreatitis: contraindicated during acute exacerbations of chronic illness.
Hypersensitivities: may need products from vegetable sources.
Growth, charts, albumin, cholesterol, glucose, CBC, iron levels, serum uric acid.
Steatorrhea: rates and intensity help monitoring dosing.
Pancreatic Enzyme Facts
Each drug is specified in lipase, protease, and amylase units. Drugs are prescribed in units of lipase.
Many older formulations are not available in FDA approved source, so finding the right dosing is more complex; this is improving over time.
Pancreatic Enzymes Education
Do not chew, crush or drink with water.
Avoid leaving in mouth.
Enteric-coated formulations should not be mixed with alkaline foods prior to ingestion.
If powder spills, wash off skin immediately.
With infants/toddlers; water for aspiration, inhalation.
Lifestyle management: follow dietary guidelines.
Insulin Pharmacodynamics
Binds at insulin receptor sites on cell membrane allowing glucose to enter cells.
Acts on liver to increase storage of glucose as glycogen.
Promotes protein synthesis on muscle cells.
Reduces circulation of free fatty acids and promotes storage of triglycerides in adipose tissue.
Types of Insulin (4)
Rapid acting
Short acting
Intermediate acting
Long acting
Rapid-acting
Lispro (humalog), aspart (novolog) or glulisine (apidra), onset about 5 minutes, peaks in 1 hour, duration about 4-5 hours.
Short-acting
Regular (humulin) insulin sometimes used around mealtime. Taken about 30-45 minutes before eating.
Peaks in 3-4 hours
Duration 4-10 hours.
Intermediate acting
Normal pressure hydrocephalus mixed with protamine, delaying absorption; insulin looks cloudy and must be mixed before it is injected.
Onset one-half to 1 hour
Peak 4 to 10 hours
Duration 12 to 24 hours
Long-acting
Glargine (lantus), detemir (levemir), degludec (tresiba) insulins.
Onset 2-4 hours
Duration 24 hours with little or no peak
Insulin Pharmacokinetics
Absorption determined by type of insulin, injection site and volume injected.
Abdominal site absorbs 50% more than other sites
Metabolism: induces CYP1A2
Excretion: urine
Watch for standardized U 100/ml, needs U100 needles.
Insulin ADR
Hypoglycemia, diabetic ketoacidosis
Watch alcohol use; increases hypoglycemia
Beta blockers mask hypoglycemia symptoms
Pregnant women can use rapid- or short-acting insulin; does not cross placenta.
-Insulin aspart, insulin glargine, and insulin glulisine
Hypothyroidism: delays insulin breakdown; therefore may require less insulin units.
Hyperthyroidism: increases renal clearance, requiring more insulin than baseline
Insulin Monitoring
Glycohemoglobin, renal function, CBC
A1C test twice a year in patients who are meeting treatment goals and have stable glycemic controls
A1C test quarterly in patients whose treatement has changed/not meeting goals
Point-of-care testing A1C allows for timely decisions on treatments changes
Insulin Patient Education
Goal A1C less than 7% for most nonpregnant adults
Individualized goals for older adults with long-time diagnoses
Administration, understanding types of insulin
Glucose monitoring frequency and recording
Emergency plan for glucose readings and “flu”
Lifestyle management, diet, exercise
Injection site selection
Oral Diabetic Agents Mechanism
Type 2 DM more than just insulin resistance
- Insufficient production of endogenous insulin. Sulfonylureas: cause an increase in insulin production.
- Tissue insensitivity to insulin. Thiazolidinediones: improve insulin sensitivity. Biguanides: do the same.
- Impaired response of beta cells. Meglitinides: increase secretion of insulin.
- Excessive production of glucose by the liver. Metformin: improves hepatic response to elevated BG, decreases glucose production and decreases GI absoprtion. Alpha-flucosidase inhibitors: inhibit absorption of carbohydrate in GI tract
- Impaired glucagon-like peptide-1 (GLP-1) activity: rapid intestinal glucose dumping. Use of dipeptidyl peptidase 4 (DPP-4) medications to slow inactivation.
- Continuous weight gain. DPP-4 may stop it or be weight neutral.
Sulfonylureas
Glipizide (glucotrol)
Glyburide (diabeta)
Glimepiride (amaryl)
All stimulate insulin release from beta cells.
All potentiate effects of ADH.
Hypoglycemia is a major side effect.
Sulfonylureas Precautions, C.I., ADR and Drug Interactions
Cross-sensitivity with sulfonamides or thiazide diuretics
Avoid in pregnant women
Older adults more sensitive to hypoglycemia events
Pediatric: use in children 10-18, but it is unlabeled.
ADRs: hypoglycemia, GI, dermatological rashes, SIADH, hemolytic anemia, leukopenia, thrombocytopenia, weight gain.
D.I.: may increase or decrease hypoglycemic effect
Sulfonylureas: Clinical Dosing for DM and DI
Clinical use and dosing for DM
- Use second-generation agents most of the time
- Individualized dose progression is based on response
- Start with lowest dose and ncrease every 4-7 days.
Neurogenic diabetes insipidus
-Chlorpropamide is used off-label.
Sulfonylureas: Rational drug selection/dosing
Age: chlorpropamide and glyburide used in older adults (use short-acting glipizide)
Cost: many generics available
Concurrent renal disease: glipizide or tolbutamide, or glyburide
Concurrent insulin: only glimepiride FDA labeled for co-administration, but most second-generation agents used
Sulfonylureas
Monitoring: Hga1c: baseline, then every 3 months while adjusting, then every 6 months.
CBC at onset, then annual unless more if symptoms
Patient education
- Administration
- ADRs
- Lifestyle management