At last count, there are more than 700 medications that potentially interact with insulin with varying degrees of significance.

Typically a negative drug interaction either decreases or increases insulin's effects, posing the risk of high or low blood glucose. But rather than insisting that you avoid these medications, it's more likely your doctor will want to adjust your insulin dosage for the period you take them.

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Commonly prescribed drugs for chronic conditions that may require an adjustment in insulin dosage include:

  • Prednisone
  • Olanzapine
  • thyroid hormones
  • ACE inhibitors
  • selective serotonin reuptake inhibitors (SSRIs)
  • sulfonamides
  • disopyramide
  • quinine and quinidine

In addition, some drugs that are prescribed for temporary conditions, such as antibiotics for infection, may require an adjustment to your insulin dosage. It's best to check drug interaction information with your pharmacist or physician, and to double-check with your pharmacist each time you refill a prescription of insulin.

By Joyce A. Generali, M.S. FASHP, R.Ph., director of the University of Kansas Drug Information Center and the author of The Pharmacy Technician’s Pocket Drug Reference

From our sister publication, Diabetes Focus, Summer 2011

Publication Review By: the Editorial Staff at

Published: 24 Apr 2011

Last Modified: 11 Sep 2015