Antidiabetics Flashcards
What is the incretin effect?
Oral glucose results in a higher insulin level compared to IV glucose due to incretins released by the gut that enhances insulin secretion.
What is the molecular pathway that leads to insulin release?
- increase blood glucose
- glucose enters pancreas via GLUT-2
- increased glycolysis and TCA cycle leading to increased ATP
- ATP closes potassium channel decreasing amt of K+ leaving cell and causing depolarization
- cell depolarization causes calcium channels to open and release pf insulin via exocytosis occurs
What are the 3 injected, rapid-acting insulin analogs?
- Insulin Lispro
- Insulin Aspart
- Insulin Glulisine
[modified B-chain]
*These are given to mimic the prandial release of insulin [given 15 minutes before meal] and given with longer acting insulins to assure proper glucose control
“There is no LAG”
Short acting insulins?
This is regular insulin that is a soluble crystalline zinc formation and is given 30 minutes before a meal. It is usually give via SC but may be given via IV in emergencies.
Intermediate-acting insulins?
Neutral protamine Hagedorn (NPH) - aka isophane insulin which is a suspension of crystalline zinc insulin combined with protamine
Given SC along with rapid- or short-acting insulin for mealtime control – helps maintain BASAL CONTROL.
Insulin Glargine?
Long-acting insulin, A chain mutation [Asn to Gly] - administered as an acidic depot solution that precipitates as glargine in the SC tissue (pH = 7.4). There is then slow dissolution of free glargine hexamers from precipitated glargine (stabilized aggregates)
Insulin Detemir?
Long-acting insulin, B chain mutation [addition of 2 Arg AA]
What are the major difference b/t insulin analogs and normal human insulin preparations?
Insulin analogs mimic physiologic insulin profiles more closely than human insulin preparations. Rapid-acting analogs have improved postprandial glycemic control and less risk of hypoglycemia. There is a better improvement of HbA1C levels and reduced hypoglycemia as compared to regular insulin or human insulin preparations.
When are IV infusions of insulin given?
- pts with ketoacidosis
- during perioperative pd
- during labor and delivery
- intensive care situations
[regular human insulin is used in IV therapy]
Basal-bolus insulin regimes?
One daily shot of glargine or detemir to provide basal coverage then doses of Lispro, Aspart, or Glulisine to provide coverage for each meal.
Long acting insulin is given t bedtime or morning and if pt skips meal, they omit the premeal bolus. An increase in premeal bolus is needed if pt eats a large meal than normal.
Insulin pump therapy?
Use of insulin pump is the best way to mimic normal insulin secretion. It is a battery-operated pump and computer program that delivers predetermined amts of insulin.
Glulisine, Lispro or insulin aspart is used in insulin pump.
AE of insulin?
- Hypoglycemia (manage with orange juice or sugar-containing beverage),
- Allergic reaction - immediate type I HSN often due to noninsulin protein contaminants
- Lipodystrophy at injection site
- Drug interactions
What drugs cause hypoglycemia?
- Ethanol - inhibits gluconeogenesis
- B-blockers - blocks effect of catecholamines on gluconeogenesis and glycolysis as well as masking sympathetically mediated symptoms of hypoglycemia
- Salicylates - enhance pancreatic B-cell sensitivity to glucose potentiating insulin secretion
What drugs cause hyperglycemia?
Counter action of insulin – Epinephrine, Glucocorticoids, Atypical antipsychotics, HIV protease inhibitors
Inhibit insulin secretion directly - Phenytoin, clonidine, Calcium channel blockers
inhibit insulin secretion indirectly by depleting potassium - diuretics
How do you manage diabetes in hospitalized pts?
Insulin administration - oral antidiabetics should be discontinued during acute illness and replaed iwth insulin