Antidiabetics 1 Flashcards
Pharmacotherapy of Type 2 Diabetes?
• Pharmacotherapy for type 2 DM includes a
number of noninsulin hypoglycemic agents.
• Most type 2 diabetics don’t require exogenous
insulin for survival but many need it to achieve
optimum health.
• 20% of type 2 diabetics in the USA take insulin.
Pharmacotherapy of Type 1 Diabetes?
• Type 1 DM patients have virtually no insulin
secretion.
• They must rely on exogenous insulin injected
SC to control hyperglycemia and avoid
ketoacidosis.
What is Insulin?
• Small protein with mw of 5808 in humans.
• 51 amino acids arranged in 2 polypeptide chains
connected by disulfide bonds.
The secretion of insulin by cells is stimulated by:
• Glucose. The most important stimulus for insulin secretion. • Amino acids. • Gastrointestinal hormones (Incretins). Released after the ingestion of food.
The Incretin Effect, what is it?
- Glucose given orally results in higher insulin levels than glucose given IV.
- This is because incretins, released by the gut, enhance insulin secretion.
Describe the Insulin Receptor?
• The insulin receptor consists of two covalently linked
heterodimers.
• Each contains an alpha subunit and a beta subunit.
• The alpha subunit is extracellular and contains the recognition site for insulin.
• The beta subunit spans the membrane and contains a
tyrosine kinase.
• When insulin binds to the alpha subunit, the tyrosine kinase is activated in the beta subunit.
• This leads to phosphorylation of tyrosine residues on the beta subunits and of cytoplasmic proteins.
Effects of Insulin on Its Targets?
Increases
Amino acid uptake by muscle
Glycolysis
Fatty acid synthesis and storage as TG in adipose tissue
Glycogen Synthesis in liver and muscle
Glucose entry in muscle and adipose tissue
Decreases
gluconeogenesis
Sources of Insulin?
• Human insulin has largely replaced insulin
isolated form beef or pork pancreas.
• Human insulin is produced by recombinant DNA
technology using strains of E coli or yeast.
Preparations of Insulin?
- Rapid-acting, with very fast onset and short duration.
- Short-acting, with rapid onset of action.
- Intermediate-acting.
- Long-acting, with slow onset of action and long duration.
There are three injected, rapid-acting insulin analogs, what are they?
- Insulin Lispro
- Insulin Aspart
- Insulin Glulisine
Rapid acting insulin: importance of hexamers?
- Native insulin monomers are associated as hexamers in currently available insulin preparations.
- These hexamers slow the absorption of insulin.
- This led to the development of short-acting insulin analogs that don’t form hexamers.
Rapid acting Insulin Lispro amino acid replacements?
Insulin Beta chain: 28-proline, 29-lysine
Lispro Beta chain: 28-lysine, 29-proline
Rapid acting Insulin Aspart amino acid replacements
Insulin beta chain: 28-proline
Aspart beta chain: 28-aspartate
Rapid acting Insulin glulisine amino acid replacement?
insulin beta chain: 3-aspartate, 29-lysine
Glulisine beta chain: 3-lysine, 29- glutamic acid
Rapid-Acting Insulins: Uses?
• Rapid-acting insulins are given to mimic the
prandial release of insulin.
• They are usually given along with a longer
acting insulin to assure proper glucose control.
• Given SC.
• Given 15 minutes before a meal.
• Also suitable for IV.