Category: Diabetes/Prediabetes/Hypoglycemia


Monday, Apr 8
1:00 AM – 2:00 AM

Objective : Sulfonylureas (SU) are considered to be mainstream therapy for diabetes mellitus (DM) type 2 due to their effectiveness, low cost, and widespread availability. However, their use in the elderly is avoided due to the potential complication of hypoglycemia. On the other hand, fluoroquinolones are not known to cause hypoglycemia, but can exacerbate the effect of SU. We report the case of an 84-year-old man who came to the hospital for severe hypoglycemia with concurrent use of levofloxacin and unknown ingestion of SU.

Methods : N/a

Results : N/a

Discussion : 84-year-old male with past medical history of DM type 2, coronary artery disease, chronic kidney disease (CKD) stage 3, Hodgkin's lymphoma and hypothyroidism who presented with severe hypoglycemia in the 20's. One week prior to admission, patient was started on levofloxacin for community acquired pneumonia. Regarding his diabetes treatment, family reported he was diet-controlled and not on any oral agents or insulin for the last 12 months. They also confirmed that no medication refills were obtained in the past 3 weeks. On arrival, patient was started on dextrose infusion and subcutaneous octreotide injections for persistent hypoglycemia. Initial labs showed C-peptide 23.7 ng/mL, Insulin 72.6 mU/L and Proinsulin 38.5 pmol/L. The hypoglycemia eventually subsided with no additional interventions and treatment was discontinued. Repeat labs 5 days later showed C-peptide 3.2 ng/mL, Insulin 7.5 mU/L and Proinsulin 4.3 pmol/L. It was recommended to avoid fluoroquinolones and verify that no SU agents were available at home. Soon after discharge, SU screen came back positive for glimepiride.

Levofloxacin is one of the most popular used antibiotics in healthcare nowadays. Awareness of levofloxacin-induced hypoglycemia in the setting of SU use is becoming more widespread; however, many providers are still unaware of this interaction. The mechanism for increased insulin secretion by fluoroquinolones is via blockade of ATP-sensitive Kchannels in the ß cells of the pancreas in a dose-dependent manner. In regards to SU, their use in elderly and CKD patients should be restricted. Providers should always consider this etiology in the differential diagnosis of hypoglycemia in diabetes population as ingestion of these agents can stem from prescription errors or medication unawareness.

Conclusion : In today's modern medicine, healthcare providers should be aware of the severe interaction between fluoroquinolones like levofloxacin and SU. In addition, SU involvement should always be considered in the DM type 2 population presenting with hypoglycemia regardless of an otherwise inconclusive history.


Gonzalo J. Acosta

Resident Physician
Houston Methodist Hospital
Houston, Texas

I am a very motivated Peruvian physician, currently on my 2nd year of Internal Medicine residency at Houston Methodist Hospital and with a great passion/interest/love for Endocrinology.

Ashkan M. Zand

Endocrinology Fellow
Houston Methodist Hospital
La Porte, Texas

Ashkan Michael Zand is currently the chief fellow at the Houston Methodist Endocrinology Fellowship program. As a native Texan, Dr. Zand attended the University of Houston in which he acquired a B.A in Chemistry and B.S. in Biology. Afterwards, Dr. Zand underwent his medical education at the University of Texas Medical Branch at Galveston where he completed his medical degree and Internal Medicine residency.

Ahmad Yehya

Endocrinology Fellow
Houston Methodist Hospital

A graduate of the American University of Beirut, Lebanon, Dr. Yehya completed his Internal Medicine Residency at the University of Kansas Medical Center. Dr. Yehya has a profound interest in metabolism and participated in various weight management programs and clinics throughout his Residency. Dr. Yehya will be working closely with the weight management program at Houston Methodist with special emphasis on weight loss medications, diet adjustment and exercise. Dr. Yehya is also particularly interested in the impact of lifestyle on diabetes. Dr. Yehya has specifically chosen to pursue his Endocrinology Fellowship at Houston Methodist as this will serve as a great template for launching a successful career in Endocrinology and he hopes to be able to develop weight management centers dedicated to focus on lifestyle changes for the community.

Steven Petak

Division Chief of Endocrinology, Diabetes and Metabolism
Houston Methodist Hospital

He is a past president of the American Association of Clinical Endocrinologists, the American College of Endocrinology, and the International Society for Clinical Densitometry. He is an associate clinical professor at Weill-Cornell Medical College at the Houston Methodist Hospital and is the division head of endocrinology, diabetes and metabolism as well as service chief of endocrinology. He is a bone densitometry and endocrine consultant to NASA at the Johnson Space Center for about 13 years and has been a part of the bone summit planning long duration space missions. He is the secretary of the board of councilors of the Texas Medical Association (2015) and represents the Harris County Medical Society as vice-councilor.

His awards include Master of the American College of Endocrinology, Yank Coble Public Service Award of the American College of Endocrinology, the ISCD Paul Miller Public Service Award, and ISCD Clinician of the Year. He has authored and co-authored articles, editorials and guidelines in endocrinology and reproductive medicine.

He received his MD from the University of Illinois in Chicago and has his JD from the University of Houston (Magna cum Laude). He had his internship, residency, medical chief residency, and fellowship in endocrinology and metabolism at the University of Texas at Houston. He was at the Texas Institute for Reproductive Medicine and Endocrinology in Houston for about 26 years before joining the academic endocrine group at Methodist in May 2013. He is board certified in internal medicine as well as endocrinology and metabolism. His wife is a veterinarian in private practice and he has 2 children, 4 cats and a dog.