L91- Pharm Diabetes Flashcards
Discuss the structure and actions of the Insulin REceptor?
Heterodimer w/ Alpha and Beta Subunits
Alpha - binds insulin
Beta - Tyrosine Kinase domain
Tetramer formation as they come together and 2 beta subunits phopshorylate eachother producing a cascade that signa;s IRS and results in GLUT4 glucose transporters traveling from sequestered sites to cell surface …and transcription of other things like Glucokinase
Which Glucose transportrers are found where?
Glut 1 - in the brain always and doesn’t need insuline for transport of glucose
GLUT2 reulgates insulin release in response to blood glucose
Glut4 - inserted into membrane in muscles and adipose cells from intracellular storage vesicles in response to insulin
IS it more efficent to store energy as fat or glycogen in muscles?
Fat TG bc glycogen needs H2O for storage vs fat does not
How long does reuglar insulin act?
1 hour
How many ppm does insulin need to be to be “purified” in instances of allergenciity?
<10ppm then purified
What are the Ultra-Short acting insulins? How do they work?
Lispro, Aspart, Glulisine
Remain in monomer form in vial and don’t form hexamers so immediate use and peak at 15 minutes
take right before meals
(regular insulin forms hexamers in vials and so inject it and have to dilute it in tissues to work so 30 minute lag)
What are the long acting insulins? What’s differences between them?
Glargine and Detemir
Glargine - Beta insulin supplement that is 18-24 hours long lasting and no discrete peak
Detemir - goes into blood and binds serum albumin and slowly released from albumin; slight peak ~12 hours and lasts 18 hours
What are the different insulin delivery systems?
Insulin is a peptide and so will be degraded orally so has to be given enterally
POrtable Pen injectors
Continuous SQ insulin infusion device aka pumps - preffered in kids and recomended for people with difficulty obtaining target control - lower total insulin dose
Inhaled - Afrezza
What are the problems/contraindications in Inhaled insulins?
Short term release
CONTRAINDICATION in patients w/ chronic lung disease - smokers, COPD, ASthma
Problem if taking and get URI
Complications of Insulin therapY?
Hypoglycemia- TX is sugar/IV glucose
Allergy
Lipodystrophy at injection site –> hypertrophy of Sq fat tissue from multiple injections at same site and liposuction corrects this
What are the different classes of oral antidiabetic drugs?
Insulin secretagogies - Sulfonylureas or Meglitinides
Biguanides
Thiazolinediones
Alpha-glucosidase inhibtors
Glucagon-like polypeptide 1 (GLP1) Agonsistss
DDP4 Inhibitors
SGLT2 Inhibitors
Sulfonylureas - mechanism of action, Important considerations, what drgs are they?
Second Generation - fewer side effects and less drug interactions but more potent so more likely to produce hypoglycemia - Glyburide, Glipizide, Glimepiride vs First generations - tolbutamide, chlorpropamide, tolazamide, acetohexamide
Mechanism: insulin release from beta cells independent of glucose!!! Activate SUR1 receptor assocaited w/ K6.2 channel
Condiseration: Pt needs functioning beta cells to make and release insulin
HYPOGLYCEMIA!
What are the Meglitinides? Mechanism? Cautions? Indications?
Repalinide (Prandin)
Mechanism: modulate beta cell insulin release, same site of action as Sulfonylureas but weaker affinity for receptors - shorter action
CAUTION - metebolized by liver so careful in pts w/ hepatic impairment
NO SULFER STRUCTURE - good for patients allergic to sulfonylureas!
What drug is a “Biguanide”? Mechanism of action? Uses?
METFORMIN!!!
Blood glucose lowering ability not dependent on function beta cells - Euglycemic
Mechanism - not completely known but increases insulin sensitivity of tissues and reduces insulin resistance, stimulates glycolysis in tissues, reduces hepatic gluconeogenesis, slows GI glucose absorption w/ increased glucose to lactate conversion, reduction in Glucagon levels
FIRSTLINE TREATMENT FOR T2DM
What are the side effects of metformin?
GI!! Anorexia, N/V, abdominal discomfort and diarrhea
Usually transient at begining of therapy
Absorption of B12 impaired!!!!