Biguanides pharmacotherapy Flashcards
Class of Drugs - Biguanides
Metformin
Generic - metformin
Brand - Glucophage or Glucophage XR
MOA - metformin (hint: primary & secondary)
Primarily = inhibits hepatic gluconeogenesis Secondly = improves insulin sensitivity in the muscles and fats --> removing glucose from systemic circulation and allowing glycolysis
Does metformin cause hypoglycemia?
No, it doesn’t
What are the two types of formulation for metformin?
Intermediate release and Extended release
What is the initial dosing of metformin in the immediate release form?
Initially: 500 mg once a day for 3-5 days
What is the maximum dose of metformin in the immediate release form?
2,550 mg (850 mg TID)
What is the initial dosing of metformin in the extended release form?
Initially: 500 mg once a day for 5-7 days
What is the maximum dose of metformin in the extended release form?
2000-2500 mg (could differentiate w/ formulations)
When can metformin be titrated up? (for both immediate and extended release)
When the patient tolerates metformin AND if they have not met their desired goal
If a patient has an eGFR < 30 mL/min/1.73 m^2, can they be given metformin?
No, it is contraindicated in patients who have an eGFR < 30
If a patient has an eGFR >/= 30 mL/min/1.73 m^2 to < 45 mL/min/1.73 m^2, can they be given metformin?
Yes, but the maximum dose will fall down to 1000 mg
If a patient has an eGFR >/= 45 mL/min/1.73 m^2, can they be given metformin?
Yes, they can be given full dose
What are the FIVE main contraindications of metformin?
- Respiratory insufficiency
- CHF
- Hepatic dysfunction
- Elderly without renal insufficiency (> 80 yo)
- Severe infections
Can metformin be used simultaneously with iodinated contrast media?
No, metformin needs to be HELD prior to initiating the contrast media and cannot be given AFTER 48 hrs from the contrast media
