Week 8: Biguanides and TZDs - Insulin Sensitizers

Question 1

Biguanides - Metformin (Glucophage) MOA

Answer 1

1) improves the sensitivity of insulin @ muscle cells
2) decreases hepatic glucose production
3) decreases intestinal absorption of glucose

Does not cause hypoglycemia

Question 2

Metformin (Glucophage) contraindications

Answer 2

• NO renal impairment (GFR < 30)
• NO in hepatic disease
• hold 48 hrs before and after radiologic contrast

BLACK BOX WARNING: lactic acidosis, hypothermia, HTN, resistance of bradyarrhytmias

Question 3

Biguanides/Metformin ADRs

Answer 3

• GI upset (common): diarrhea/gas
• Lactic Acidosis (in dehydration)
• vitamin B12 deficiency

Question 4

Metformin pt counseling

Answer 4

Hold for 48 hours before and after radiologic studies with contrast

Question 5

Thiazolidinediones (TZDs) - Pioglitazone (Actos) MOA

Answer 5

1) enhances insulin sensitivity
2) increases utilization of available insulin by the liver and muscle cells as well as adipose tissue.
3) decreases hepatic glucose production
* *works exactly like Metformin then went terribly wrong**
- Does not cause hypoglycemia - Weight positive

Question 6

TZDs - Pioglitazone (Actos) ADRs

Answer 6

• fluid retention –> peripheral edema
• weight gain
• HTN
• small bone fracture
• increase risk of bladder cancer and hepatotoxicity

Question 7

Pioglitazone (Actos) contraindications

Answer 7

• NO in heart failure
• active liver dz (ALT greater than 2.5x above normal limits)
• NO in hx/active of bladder cancer

Question 8

Actos (TZDs) pt education

Answer 8

LFT before therapy