Metformin & Sulfonylureas

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Metformin & Sulfonylureas
2011-09-16 20:35:45
james donaldson James Donaldson metformin

Someone please beat Mayweather.
Show Answers:

  1. Which oral agent for diabetes is available as a liquid solution?
    Metformin (Riomet)
  2. True or False?
    Metformin has the potential to cause hypoglycemia as well as renal failure.
    • False.
    • Metformin does not CAUSE hypoglycemia if taken as monotherapy and does not CAUSE renal failure - though it should be used with caution in cases of renal failure.
  3. Why should metformin be used with caution in patients with renal impairment (or CHF - perfusion to kidneys) (or hepatic impairment - lactate cleared by liver)?
    There is no hepatic metabolism present; 90% of metformin is excreted renally as unchanged drug. If renal failure is present, risk for lactic acidosis!
  4. When is metformin (glucophage) contraindicated?
    • 1. Female SCr ≥ 1.4
    • 2. Male SCr ≥ 1.5
    • 3. Elderly GFR < 70 mL/min (from 24 hour urine collection)
    • 4. Patient's in ICU
    • *Risk for lactic acidosis*
  5. What should be done if a patient on metformin (glucophage) needs to recieve iodinated contrast dye?
    Hold metformin for 1-2 days before and 2 days after administration of the dye.
  6. True or False?
    Titration of metformin should be utilized to avoid hypoglycemic effects?
    • False.
    • Titration should be utilized to avoid GI side effects.
  7. What is the initial dose of metformin (glucophage) IR? How should it be titrated? To what max dose?
    • 500 mg po BID or 850 mg po qd.
    • If no GI side fx in 5-7 days, increase dose.
    • 500 mg po BID --> 1000 mg po BID
    • 850 mg po qd --> BID --> TID
  8. What is the max effective dose of metformin (glucophage)? What is max FDA allowable dose?
    • 2000 mg/day
    • 2550 mg/day

    *80% of effectiveness seen at 1500 mg/day*
  9. True or False?
    There are less GI side fx seen with metformin XR (glucophage, rumetza, fortamet) dosing.
  10. What are the doses of metformin XR (glucophage, rumetza, fortamet)?
    • XR 2000 mg po qd with evening meal
    • If suboptimal, change to XR 1000 mg po BID
  11. How should a patient on metformin be monitored?
    • 1. SCr and CrCl at least annually (q 3-6 months in patients at risk for renal dysfunction)
    • 2. SMBG (stable dose and A1C --> 3-4 days/week, if dose being titrated --> once daily)
    • 3. Vit. B12 in cases suspicious for deficiency
    • 4. CBC annually
  12. Who should receive metformin?
    ALL patients at time of DMII diagnosis who do not have any contraindications for its use.
  13. True or False?
    1. Has positive effects on TGs and HDL
    2. Should not be used in pts with CHF
    3. Is the only diabetic drug proven to reduce risk of mortality
    4. Has a duration of action of about 24 hrs
    • 1. False - TGs and LDL
    • 2. False - may be used in stable cases of CHF, even in pts older than 80 yrs (target to 1500 mg/day)
    • 3. True
    • 4. True
  14. True or False?
    2nd generation sulfonylureas are more effective than 1st generation sulfonylureas.
    • False.
    • They are equally effective.
    • 2nd generation sulfonylureas are more potent and have less protein binding, and also have fewer drug/drug interactions.
  15. True or False?
    2nd generation sulfonylureas cause less hypoglycemia compared to 1st generation.
  16. Which sulfonylureas are hepatically metabolized to inactive metabolites?
    This makes them preferable for pts with ________.
    • 1. glipizide (Glucotrol)
    • 2. glimiperide (Amaryl)
    • *Renal insufficiency*
  17. Which sulfonylureas are hepatically metabolized to active metabolites? This makes them non-ideal for pts with _______.
    • 1. glyburide (DiaBeta, Micronase)
    • 2. micronized glyburide (Glynase)
    • *Renal insufficiency*
  18. True or False?
    Agents that increase insulin production cause weight gain.
    According to Dr. Thomas, as a rule of thumb, this is true.
  19. What are two common adverse effects associated with sulfonylureas?
    • 1. hypoglycemia (the lower the FPG on initiation, the higher the likelihood)
    • 2. weight gain
  20. True or False?
    Disulfuram reactions have been noted with 2nd generation sulfonylureas.
    • False.
    • Noted with 1st generation sulfonylureas when taken with EtOH
  21. Sulfonylureas are ineffective when FPG > _____ mg/dL. In this case, what should be done first?
    • > 300 mg/dL
    • Administer insulin first, normalize BG, and then add SU.
  22. When should sulfonylureas be taken?
    30 minutes prior to meals - in order to give time for insulin to be realized from pancreas.
  23. True or False?
    Sulfonylureas may cause weight gain.
    • True.
    • It looks like, as a rule, if insulin secretion is increased per drug MOA, weight gain is a possibility.
  24. While on a sulfonylurea, how often should a patient check their blood glucose?
    • - At least once daily while dose is being titrated
    • - 3-4 x/week if dose is stable and A1C is controlled
  25. What 3 things should be monitored by a clinician for a patient on a sulfonylurea?
    • 1. Frequency of hypoglycemia (every visit)
    • 2. Renal function (q 3-6 months or at least annually)
    • 3. Weight (every visit)
  26. True or False?
    The combination of metformin and a sulfonylurea may cause hypoglycemia.
    • True.
    • Metformin may be responsible for hypoglycemia when combined with a sulfonylurea - the condition is most likely attributable to the SU.
  27. True or False?
    Monotherapy with metformin may be adequate to control a patients blood glucose levels.
  28. True or False?
    Monotherapy with a sulfonylurea is usually sufficient to control a patients blood glucose levels.
  29. True or False?
    A synergistic effect is seen when sulfonylureas are combined with metformin.
  30. Explain the phenomenon of secondary failure with SUs.
    • Primary failure = drug never controls BG levels
    • Secondary failure = SUs may control BG levels for a while and then efficacy diminishes.
  31. Patients who are _________ __________ are at risk for hemolytic anemia while taking ___________.
    glucose-6-phosphate deficient, sulfonylureas