T2DM pt 2 Flashcards
Sitagliptin dosing
25, 50, or 100 mg po daily
Saxagliptin dosing
2.5 or 5 mg po daily
linagliptin dosing
5 mg po daily
alogliptin dosing
25 mg po daily
DPP-4 inhibitors advantages
administered orally
reduce hyperglycemia and HgbA1c
low risk of hypoglycemia
considered weight neutral (no significant weight loss, usually co-administered with weight loss drug)
available in combination with metformin
Januvia and Nesina are excreted in the?
urine, kidney
Tradjenta is excreted in the?
feces, liver
Onglyza is excreted in the?
urine, kidney
Januvia, Nesina, and Tradjenta metabolism
not extensively metabolize
Onglyza metabolism
CYP3A4/5 substrate, major metabolite is active
DPP-4 inhibitor side effects
N/V, constipation, headache, severe skin reactions, pancreatitis, joint pain, HF
DPP-4 on immune cells
off target effects that cause reduced white blood cell counts (infections) and a potential increased risk of cancers
Pramlintide
amylin analog
37 aa peptide, normally co-secreted with insulin
Pramlintide mechanism
slows gastric emptying, decreases food intake, and inhibits glucagon secretion, blunts postprandial rise in BG
Useful in both Type 1 and Type 2 diabetes
Pramlintide dosing
used in conjunction with insulin
injected SC
a-glucosidase inhibitor drugs
acarbose (Precise)
miglitol (Miglitol)
a-glucosidases
enzyme located in the intestinal brush border that is used to break down carbs into simple sugars (glucose)
a-glucosidase inhibitor mechanism
decrease the absorption of carbohydrate from the intestine via inhibition of gut a-glucosidases
a-glucosidase inhibitor place in therapy
taken orally with meals to reduce postprandial glucose surge
a-glucosidase inhibitor absorption
acarbose is only minimally absorbed
miglitol is completely absorbed
a-glucosidase inhibitor adverse effects
GI - diarrhea, nausea, flatulence
risk of liver damage at acarbose doses > 100 mg tid
SGLT2 inhibitor drugs
Canagliflozin (Invokana)
Dapagliflozin (Farxiga)
Empagliflozin (Jardiance)
Ertugliflozin (Steglatro)
Bexagliflozin (Benzavvy)
SGLT2 glucose transporter
located on the PCT, responsible for 90% of glucose reabsorption
SGLT2 inhibitor Mechanism
block the SGLT2 glucose transporter, increases urinary excretion of glucose
SGLT2 advantages
decreases A1c as monotherapy with metformin or sufonylureas
significant weight loss observed with monotherapy
SGLT2 disadvantages
increased risk of genital/UT infections
increased urine flow/volume depletion/hypotension
increased risk of diabetic ketoacidosis (DKA)
increased risk of lower limb amputation
contraindicated in patients with renal impairment (eGFR>30ml/min/1.73m^2)
SLGT2 inhibitor place in therapy
indicated for type 2 diabetics as an adjunct to diet and exercise
not used in type 1 diabetics (increased risk of DKA)
Biguanides
Metformin (Glucophage)
Thiazolidinediones
Pioglitazone (Actos)
Rosiglitazone (Avandia)
Insulin resistance
decreased responsiveness to insulin
insulin resistance characterized by
OGTT with prolonged elevation of plasma glucose with normal or elevated insulin levels
causes of insulin resistance
polymorphisms in insulin signaling pathway proteins (rare)
obesity - especially accumulation of fat in the abdominal cavity
inactivity
insulin resistance in skeletal muscle
impaired glucose uptake
insulin resistance in adipose tissue
impaired glucose uptake
impaired inhibition of lipolysis
mobilization of FAs to other tissues
insulin resistance in liver
impaired inhibition of glucose output (via gluconeogenesis or glycogenolysis)
link between obesity and insulin resistance
free fatty acid (FFA) levels are increased in obese people
acute raising FFA levels cause insulin resistance (IR)
acute lowering of plasma FFA levels reduces chronic IR
increase FFA and insulin resistance
Serine is phosphorylated instead of Tyrosine on IR and IRS proteins which inhibits signaling. This is promoted by FA uptake, lipid byproducts, and inflammatory mediators
Metformin
classified as an anti hyperglycemic agent
decreases blood glucose concentrations in NIDDM without the concentration falling below normal
biguanides advantages
rarely cause hypoglycemia
rarely cause weight gain
Metformin Mechanism
activator of AMP-activated kinase (AMPK) increases the efficiency or sensitivity to insulin in liver (decreased gluconeogenesis, fat, and muscle cells (increased glycolysis, glucose uptake)
metformin dosage
500-850 mg BID/TID before meals (to eliminate diarrhea)
can be used in combination with sulfonylureas
metformin mechanism in the liver
- inhibits mitochondrial respiration via complex 1 inhibitiion
- increase in AMP:ATP ratio and ADP:ATP ratio which decreases the energy availability of the cell
- glucagon receptor is inhibited leading to decreased cAMP signal
- decreased cAMP signal effects many downstream signals leading to decreased lipid and cholesterol synthesis
- Increased AMP inhibits FBPase, an enzyme required in gluconeogenesis
- Decreased gluconeogenesis decreases glucose production
Metformin contraindications
patients with disorders which increase the tendency towards lactic acidosis (occurs in patients with a hard time getting oxygen to the heart and lung tissues)
Metformin mechanism in the skeletal muscle
- During exercise the skeletal muscle burns up ATP and causes a build up of AMP
- Build up of AMP during exercise activates AMPK
- AMPK phosphorylates TBC1D1/4 which promotes GTPase activity of Rab
- Rab dissociates from GLUT4, allowing translocation
Metformin AEs
decreased vitamin B-12
GI discomfort (N/V/D)
metformin effects on lipid profile
decreased serum triglycerides
decreased serum LDL
reduced risk of adverse CV events
Canagliflozin dosing
100 or 300 mg daily
dapagliflozin dosing
5 or 10 mg daily
ertuglifloxin dosing
5 or 10 mg daily
bexagliflozin dosing
20 mg daily
empagliflozin dosing
10 or 25 mg daily
Thiazolidinediones effect
decrease insulin resistance or improve target cell response to insulin
Thiazolidinediones Mechanism
activates of peroxisome proliferator-activated receptor gamma (PPARy), a transcription factor
TzDs effect in the liver
enhances glucose uptake
reduced hepatic glucose production
TzDs effect in adipocytes
main target
- enhances adipocyte differentiation
- enhances FFA uptake into SC fat
- reduces serum FFA
- shifts lipids into fat cells from non-fat cells
TzDs effect in skeletal muscle
enhances glucose uptake
Rosiglitazone dosing
4-8 mg once daily
Pioglitazone dosing
15-30 mg once daily
TzDs contraindications
NYHA Class III/IV heart failure
TzDs advantages
do not cause hypoglycemia
TZDs disadvantages
Pioglitazone is associated with an increased risk of bladder cancer
both can cause some hepatoxicity (check liver function)