Insulin and Hypoglycaemics Flashcards
Beta cells help control blood glucose by producing insulin. What helps to produce glucagon?
alpha cells
What are the functional effects of insulin?
- changes glucose in to glycogen or fat
- turns glucose into amino acids and amino acids into proteins
- decrease glucose formation
- stimulates glut4 which moves glucose upto the cell membrane and therefore
- leads towards hypoglycaemia
What is the difference in definition of type 1 and type 2 diabetes?
type 1 - insulin producing cells are destroyed and insulin MUST be provide
type 2 - insulin producing cells are failing tissues or insensitive to insulin
blood glucose levels elevated because body can not utilize it properly
What are the risk factors for type 2 diabetes?
- age
- obesity
- ethnicity
- family history
When treating people with type 1 diabetes there is 3 basic insulin preparations. What are they?
- short duration - rapid onset
- intermediate action
- longer lasting- slower in onset (contains zinc)
Examples of short acting insulins used to treat type 1 diabetes are insulin aspart, insulin glulisine and insulin lispro. What are the timings of these drugs?
- rapid on set - 30-60 minutes
- peak action: 2-4 hours
- duration: 8 hours
injected just before, with or just after food and only lasts long enough for the meal at which it is taken for.
What are examples of intermediate and longer duration insulins used to treat type 1 diabetes?
insulin detemir insulin glargine insulin suspension isophane insulin protamine zinc insulin
What are biphasic insulins?
biphasic insulin preparation
- mixture of intermediate and fast acting
- they have rapid onset
- longer-lasting actions
insulin can be administered subcut, via pens or via portable infusion pump. What is the difficulty with the infusion pump?
- it is a close loop system and therefore can not help if glucagon is needed in a hypoglycaemic episode
Hypergylcaemia- inducing drugs must be used when blood glucose goes to low. these are given via injections. what do they do and what are their side effects?
- acutely raises plasma glucose levels
- side effects include headache and nausea
- they must be reconstituted prior to use
What is the mode of action for secretagogues ?
- boost insulin release
- enhances the normal physiology of glucose-stimulated insulin secretion
- acts as antagonist of the potassium pumps
How do meglitinides such as repaglinide and nateglinide work? *secretagogues 1
- small molecule antagonist of the potassium channel
How long do meglitinides such as repaglinide and nateglinide last? and what is a benefit of these? *secretagogues 1
- they are short acting
- may have a decreased risk of hypoglycaemia compared with SUs, particularly in the elderly
What is the specific mode of action in secretagogues 2 such as exenatide and liraglutide?
- peptide agonist of the GLP-1 receptor and not broken down by DPP4
What are examples of secretagogues 2.
- exenatide
- liraglutide
- byetta
- victoza
What is a benefit of secretagogues 2?
much reduced risk of hypoglycaemia compared to sulphonylureas
- can be combined with metformin
What are the action of secretagogues 3 such as gliptins, sitagliptin and vildagliptin?
inhibitors of DPP4
raises the half- life of serum GLP1
How are secretagogues 3 such as gliptins, sitagliptin and vildagliptin administered?
oral tablet
What are the actions of Diazoxide?
small molecule agonist of the potassium channel
- it is a hyperglycaemia therapy
How is the hyperglycaemia therapy diazoxide administered?
orally and must be with chlorothiazide because promotes water absorption!
What is dioxide used to treat?
severe hyperglycaemia
congenital hyperinsulinism in infancy
What do insulin sensitizers do ?
help improve the sensitivity of target organs to insulin
What two types of drugs are part of insulin sensitizers?
- biguanides
- Thiazolidins
What are the modes of action in biguanides?
- prevents hepatic production of glucose
- overcomes insulin resistance by improving sensitivity
What is an example of a biguanide?
metformin
What are the benefits of metformin (a biguanide)
- can be used in combination with other drugs to treat type 2 diabetes
- best choice of drug for people who also have heart failure
What are the actions of thiazolidinediones/ glitazones?
activates PPARy- a regulatory protein involved in the transcription of insulin-sensitive genes which regulate glucose and fat metabolism.
principle target = adipocytes
What are examples of thiazolidinediones/ glitazones?
- Rosglitizone
also combined with metformin - avandamet
What are the actions of modifying glucose breakdown drugs??
- a-glucosidase converts oligosaccharides to glucose
- acarbose inhibits this enzyme
- absorption of starchy foods is slowed (slowing down rise in blood glucose following a meal)
What are the actions of enhancing glucose release drugs?
- glucose reabsorption
- SGLT2 (sodium-coupled glucose transporter) inhibitors cause excess glucose to be elimated in the urine ; reducing hyperglycaemia
What are potential advantages of enhancing glucose release drugs / SGLT2 inhibitors?
weight loss
insulin independent
low risk of hypoglycaemia
osmotic diuresis reduces hypertension
What are examples of SGLT2 inhibitors/ enhanced glucose release drugs ?
dapaglifozin
canagliflozin
empagliflozin
* all end in flozin
What are the treatment options for type 1 diabetes?
- insulin therapy
- islet/pancreas transplantation
- prevention: immune-mediated destruction of B-cells
