Pharmacology Flashcards
What are the actions of insulin?
- simulates amino acid uptake by cells
- protein formation
- conversion of glucose to fat in adipose tissue
- induces glucose uptake and utilisation by cells
- lowers blood glucose levels
- promotes glycogen formation
What are the two categories of type 2 DM drugs?
- insulin-dependent: increase secretion of insulin or decrease insulin resistance
- non insulin-dependent: slow glucose absorption or enhance glucose excretion by the kidneys
What is the process of secretion of insulin?
- elevation of blood glucose
- increased diffusion of glucose into beta cell by fac.diff with GLUT2
- phosphorylation of glucose by glucokinase
- glycolysis of glucose-6-phosphate to give ATP
- ATP causes closure of K+ channels so membrane depolarisation
- Ca2+ channels open and Ca2+ moves in
- insulin secretion
What are the features of sulphonylureas?
- insulin secretagogues
- eg tolbutamide
- cause Katp channel closure so there is more insulin and less blood glucose
- oral, different lengths of action
- reduce microvascular complications long-term
- can cause hypo eg in patients with reduced hepatic or renal function
- used in patients who can’t have metformin or used with metformin
What are the features of glinides?
- cause closure of Katp so there is less insulin release
- eg repaglinide
- oral, rapid onset for after a meal
- can be used with metformin
What is the normal pathway with GLP-1 and GIP in the body?
- ingestion stimulated release of GLP-1 and GIP from SI
- enhances insulin release to there is more glucose uptake
- GLP-1 decreases glucagon so there is decreased glucose
- overall DECREASE in blood glucose
- this process is decreased in diabetes
What do DPP-4 inhibitors do?
- inhibits the enzyme that terminated GLP-1 and GIP so they can work harder to decrease blood glucose
- used less than other drugs
What are the features of incretin analogues?
- mimic the action of GLP-1
- increase insulin, decrease glucagon, slow gastric emptying and decrease appetite
- SC and don’t cause hypo
What are the features of biguanides?
- eg metformin
- decreases micro complications
- oral
- doesn’t cause hypo
- causes weight loss
- can be combined with other medications
- can cause GI upsets
What are the actions of biguanides?
- decreases hepatic gluconeogenesis
- decreases glucose uptake by skeletal muscle
- decreases carbohydrate absorption
- increases fatty acid oxidation
What are the features of thiazolidinediones?
- enhance insulin’s action and activate PPARgamma
- activated PPARy acts as a transcription factor to promote coding of insulin signalling molecules
- doesn’t cause hypo
- can cause increase in weight, fluid retention and fractures
What are the actions of thiazolidinediones?
- promotes fatty acid storage in adipocytes
- decreases hepatic glucose
- enhances peripheral glucose uptake
What are the features of SGLT2 inhibitors?
- not dependent on insulin
- block reabsorption of glucose in proximal tubule so there is decrease in glucose and the patient will pee out sugar
- cardiovascular benefit
- there is no risk of hypo
How do sulphonylureas cause hypo?
beta cells make insulin despite the glucose level so this causes hypo
Why do incretins not cause hypo?
they cause an increase in insulin when there is already a trigger so there is no hypo risk
