Pharm 18- Diabetic Drugs Flashcards
Where is the pancreas found?
“Tucked in” the angle formed by the gastric pylorus and the proximal duodenum
Two functions of the pancreas
Exocine (various digestive enzymes)
Endocrine
What does the endocrine pancreas produce?
Insulin ("fed" state) Glucagon ("hungry" state) Gastrin Somatostatin Many others
What secretes insulin?
Beta cells
What does insulin do?
causes blood glucose to go down (fed state, you want to stash that energy)
What do alpha cells do? Where are they?
Endocrine pancreas; secrete glucagon which causes blood glucose to go up
What do delta cells do? Where are they?
Endocrine pancreas; secrete somatostatin which regulates a lot of things
What does the exocrine pancreas release?
Bicarb and digestive zymogens to break down fats and proteins
Two types of Diabetes
Diabetes insipidus
Diabetes mellitus
What is diabetes insipidus?
Doesn’t produce or kidneys don’t respond to vasopressin (ADH); produces a lot of dilute urine no matter how hydrated you are
What are the types of diabetes mellitus?
Type 1
Type 2
Type 3 “Other” DM
Gestational DM
All DM is characterized as an ___________ or _________ deficiency of what?
Absolute; relative; insulin
Type 1 DM
Insulin-Dependent DM (IDDM)
Type 2 DM
Non-Insulin Dependent DM (NIDDM)
What is an absolute insulin deficiency?
Type 1 DM
What is a relative insulin deficiency?
Type 2 DM
What type of diabetes is classically childhood diabetes?
Type 1
Age of Onset: Type 1 vs Type 2
Type 1: Usually during childhood or puberty
Type 2: Commonly over age 35
Nutritional status at time of onset: Type 1 vs Type 2
Type 1: Commonly undernourished
Type 2: Obesity usually present
Prevalence: Type 1 vs Type 2
Type 1: 5-10% of diagnosed diabetics
Type 2: 90-95% of diagnosed diabetics
Genetic predisposition: Type 1 vs. Type 2
Type 1: Moderate
Type 2: Very strong
Defect of deficiency: Type 1 vs Type 2
Type 1: B cells destroyed, eliminate production of insulin
Type 2: Inability of B cells to produce appropriate quantities of insulin; insulin resistance; other defects
Which type of diabetes must receive insulin?
Type 1
What are the 4 “Classic” symptoms of Type 1 DM
- Polyphagia (eat a lot)
- Polyuria (urinate a lot)
- Polydipsia (drinking)
- Weight loss
Others (wounds wont heal, sexual dysfunction, blurred vision bc glucose builds up, etc)
Which type of diabetes produce variable amounts of insulin and exhibit insulin resistance?
Type II DM
What type of therapy does Type II DM typically require?
Increasing doses of insulin and combination therapy with other antihyperglycemics
What causes Type 3 DM: “Other”? What is the course/tx?
Due to side effects of drugs, toxins, viral infections, genetic predisposition, etc.; variable in course/treatment
When could Type 4 DM: Gestational occur?
Women may develop extreme insulin resistance during their third trimesters of pregnancy as a result of hormone changes
How is Type 4 Diabetes controlled?
Controlled with insulin
What happens is Type 4 diabetes is not controlled?
Can lead to extremely large babies, dystocia, and neonatal hypoglycemia
Dystocia
difficult birth, typically caused by a large or awkwardly positioned fetus, by smallness of maternal pelvis or by failure of uterus and cervix to contract and expand normally
What is insulin?
A small polypeptide consisting of two chains (A and B) connected by a disulfide bond.
What is the half-life of insulin?
3-5 minutes
Why are plasma insulin levels not an accurate measure of insulin production?
REmoved from the circulation so rapidly (3-5 minutes)
What is a better guide for insulin production?
C-protein measurement
C-Protein
31 amino acid peptide used to differentiate Type 1 DM from Type 2 DM
What is the half-life of C-protein?
30 minutes
How many x as much insulin in the blood stream?
5x as much in the blood stream
What produces insulin?
B-cells in the pancreas in response to glucose (archetypical “fed state”)
What does insulin’s main effect target tissues?
Liver, fat, muscle
Insulin exhibits ________ effects on target tissues.
Anabolic
Anabolic
construct molecules from smaller units
What is insulin increasingly being used for by perfusionists? In conjunction with what?
Hyperkalemia therapy
Often in conjunction with glucose to drive potassium intracellularly
What else can you do to lower potassium levels?
Dialysis (not really on bypass)
Z buf; hemoconcentrator
Bicarb will drive potassium intracellularly
What types of protocols have become more common since perfusionists have started to seek much “Finer” control of glucose levels on bypass?
Insulin drip and anti-hyperglycemic protocols
Types of insulin (Rapid onset/ short acting)
Regular insulin (Humulin R, Novolin R) Insulin aspart (Novolog) Insulin glulisin (Apidra) Insulin Lispro (Humalog)
Given IV or SQ
What insulin can be given IV on bypass?
Regular insulin (Humulin R, Novolin R)
Types of insulin (Intermediate onset)
Neutral Protamine Hagedorn (NPH) insulin
(Humulin N, Novolin N)
Only given SQ
Types of insulin (long acting)
Insulin glargine (Lantus) INsulin detemir (Levemir)
Do not mix with other types of insulin
Fatty-acid side-chain attachments allow long acting insulins to do what?
Cause them to bind albumin for longer action
What is the goal of various mixtures compatible insulin?
MInimize hyper- and hypoglycemia
ADA recommends diabetics’ blood glucose (BG) maintain a mean of what?
154 mg/ml
Long-term BG measurement is via what?
Glycated (Glycosylated) Hb (HbA1c)
Normal HbA1c
<5.7%
DM target
<7.0%
Injectable Antihyperglycemics
Pramlintide (Symlin); B-cells in the islets of langerhans made this
What is Amylin?
A polypeptide released by the pancreas in conjuction with insulin
How does Amylin work?
With insulin to moderate physiologic glucose levels by slowing gastric emptying and digestion
Why is it important for digestion to be slowed in regards to Pramlintide (Symlin)?
Slow digestion allow Pramlintide (Symlin) to spread out glucose absoprtion over a longer period
How is Pramlintide (Symlin) given?
SQ at meals
What does Pramlintide (Symlin) cause?
Post-prandial satiety which has potential for future uses
What are examples of Incretin Mimetics?
Exenatide (Byetta) - Short acting
Liraglutide (Victoza) - Long acting
Both given SQ prior to eating; side effects:GI
What are incretins?
Hormones released by the GI tract post-prandially that stimulate the pancrease to release insulin, slow gastric emptying, decrease glucagon release, and encourage B-cell growth
What are oral Insulin “Adjuncts”?
Often used as part of progressive combination therapy for Type 2 DM
What are some oral insulin “Adjunct” examples?
Insulin Secretagogues Insulin Sensitizers Alpha-Glucosidase Inhibitors Dipeptidyl Peptidase IV inhibitors Sodium Glucose Co-Transporter Inhibitors (SGLT Inhibitors)
How do insulin secretagogues work?
Increase B-cells production of insulin (so critter must still have functioning pancrease), lower hepatic glucose production and increase peripheral insulin sensitivity
How do insulin sensitizers work?
Increase peripheral cellular sensitivity to insulin without increasing insulin secretion
What do Biguanides work?
Prevents hepatic gluconeogenesis; this is very important because hepatic glucose production is the main source of excessive glucose in Type 2 DM
What are biguanides often used in combination with?
Insulin or other oral antiglycemics
What is a very common side effect with biguanides?
Diarrhea
Thiazolidinediones
Increase intracellular receptors in skeletal muscle, liver, and adipose tissue to become more sensitive to endogenous insulin
What are side effects of thiazolidinediones?
Weight gain, liver damage, and increased CV risks
How do alpha-glycosidase inhibitors work?
Reversibly inhibiting an enzyme in the small intestines that helps digest polysaccharides into simple sugars. This delays complex sugar digestion which spreads out the post-prandial blood glucose spike. Don’t cause hypoglycemia by themselves but will contribute significantly in the combination RX
How do dipeptidyl peptidase-IV inhibitors work?
Work at the cellular level to increase post-prandial insulin release while inhibiting glucagon (insulin’s physiologic antagonist )release
SGLT
Sodium Glucose Co-Transporter Inhibitors (SGLT Inhibitors)
SGLT2
Low affinity, high capacity transport mechanism in the proximal tubule; designed to capture glucose lost in the renal filtration
SGLT2 Inhibitors
Glucose freely lost in the urine with fairly predictable side effects
Why was dapaglifozin (Farxiga) not approved in the US?
6-fold increase in bladder cancer; but still extensively used in Europe; Astra Zenica got it approved