Dr. Basen describes his experience and shares data from a handful of studies This article looked at trials that have examined the effects of antibiotic use on glucose levels in patients with diabetes. One 2013 study looked 78,000 patients with diabetes from January 2006 to November 2007. They examined the effects of 3 different classes of antibiotics on blood sugar swings: fluoroquinolones, second generation cephalosporins, and macrolides. The study recorded the number of emergency department visits or hospitalizations due to blood sugar swings in the 30-day period after starting antibiotics. Results showed that people with diabetes using oral fluoroquinolones are at highest risk for severe blood sugar swings. The absolute risk of hyperglycemia per 1000 individuals was 6.9 for moxifloxacin, 3.9 for levofloxacin, and 4.0 for ciprofloxacin. The absolute risk of hypoglycemia was 10 per 1000 individuals taking moxifloxacin, 9.3 for levofloxacin and 7.9 for ciprofloxacin. In comparison, the absolute risk of hyperglycemia per 1000 individuals was 1.6 for those taking macrolides and 2.1 per 1000 for those taking cephalosporins. For hypoglycemia, the absolute risk per 1000 was 3.7 for macrolides and 3.2 for cephalosporins. Dr. Lai, the lead investigator of the study, suggested that moxifloxacin was the drug associated with the highest risk of hypoglycemia, followed by levofloxacin and ciprofloxacin, and that other antibiotics should be considered if dysglycemia is a concern. The study does suggest causation mainly with fluoroquinolones and macrolides, however further studies are needed. There appears to be a gap in prior research to evaluate this finding. Health care providers should advise patients to notify them of difficulty managing their blood sugars with antibiotic use. Further research to create standard guidelines may also be helpful. The usual winter cold just seemed to linger and not go away. It had been 2 weeks of nasal congestion, runny nose and cough, but now I had sinus pressure and little to no energy. Fortunately, my blood sugar was in range the entire 2 weeks despite such awful symptoms. I then went on azithromycin, or the well-known Z-pack, for a sinus infection. I took the medication with dinner and then 2-3 hours after I felt even more fatigued, with dry mouth and a headache. I checked my blood sugar and noticed it was 270mg/dl. I jogged my mind to figure out why I was experiencing such hyperglycemia. I did not eat anything unusual for dinner and this was around 3 hours post-prandial. Nonetheless, I decided to stack insulin and take 2 more units of rapid acting insulin or my insulin aspart (Novolog Flexpen). Thirty minutes later I rechecked my blood sugar level and noticed it had not budged and remained high at 250mg/dl. Could this be secondary to the Z-pack? I had not taken an antibiotic in several years thus was unsure of its effects on blood sugar levels. Still, I wanted to properly finish the course of antibiotics and continued taking azithromycin. Much to my dismay every day the same blood sugar spikes occurred approximately 2 or 3 hours after taking the antibiotic. It did not seem to affect my blood sugar postprandially, but rather raised my fasting levels. For the last 2 days of the antibiotic course I increased my insulin glargine (Lantus) by about 20% and noticed some improvement in blood sugar control. Specifically, I normally inject 10 units of Lantus nightly and I decide to add 2 units in the morning as well. After a difficult few days of managing my diabetes, I decided to research if there are trials examining the effects of antibiotics on blood sugar levels in those with type 1 diabetes (T1D). There is one study published in Clinical Infectious Diseases in 2013 that examined 78,000 individuals with diabetes in Taiwan from January 2006 to November 2007. Specifically, the research team led a population-based cohort study and examined effects of three different classes of antibiotics on severe blood sugar swings. The antibiotics included fluoroquinolones (levofloxacin, ciprofloxacin or moxifloxacin), second-generation cephalosporins (cefuroxime, cefaclor, or cefprozil) or macrolides (clarithromycin or azithromycin). The research team then recorded the number of emergency department visits or hospitalizations secondary to blood sugar swings in a 30-day period after initiating antibiotics. The results indicated that people with diabetes using oral fluoroquinolones are at the greatest risk for severe blood sugar swings compared with the other the antibiotic classes. Specifically, the absolute risk of hyperglycemia per 1,000 individuals studied was 6.9 for moxifloxacin, 3.9 for levofloxacin, and 4.0 for ciprofloxacin. The absolute risk of hypoglycemia was 10.0 for moxifloxacin, 9.3 for levofloxacin, and 7.9 for ciprofloxacin. By comparison, among diabetes patients taking antibiotics in the macrolides class, the absolute risk of hyperglycemia was lower, at 1.6 per 1,000, and 2.1 per 1,000 among those taking antibiotics in the cephalosporin class; for hypoglycemia, the absolute risk per 1,000 was 3.7 for macrolides and 3.2 for cephalosporins, respectively. Dr. Lai, the lead investigator, and his colleagues, stated, "Our results identified moxifloxacin as the drug associated with the highest risk of hypoglycemia, followed by levofloxacin and ciprofloxacin." "Other antibiotics should be considered if dysglycemia is a concern, such as a beta lactam or macrolide." It is important to note that there are very few studies detailing the direct effects of antibiotics on blood sugar levels. This study certainly does suggest some causation mainly with fluoroquinolones and macrolide classes, but it is also well known that infection itself can lead to blood sugar fluctuations. My own personal experience did correlate azithromycin with elevated fasting blood sugar levels, but this is merely anecdotal. However, my goal in writing this is highlight the wide gap in both research and healthcare professionals' awareness of a potential link between antibiotics and blood sugar fluctuations. Therefore, healthcare professionals should always advise patients with diabetes to notify them if a certain antibiotic is causing difficulty with managing their blood sugar. Hopefully, in the future continued research may also lead to more standardized guidelines for managing diabetes while initiating a new antibiotic. Source
