A randomized, double-blind, crossover study of the effect of the fluoroquinolone moxifloxacin on glucose levels and insulin sensitivity in young men and women.

AIM

The voltage-gated potassium channel K 11.1 is important for repolarizing the membrane potential in excitable cells such as myocytes, pancreatic α- and β-cells. Moxifloxacin blocks the K 11.1 channel and increases the risk of hypoglycaemia in patients with diabetes. We investigated glucose regulation and secretion of glucoregulatory hormones in young people with and without moxifloxacin, a drug known to block the K 11.1 channel.

MATERIALS AND METHODS

The effect of moxifloxacin (800 mg/day for 4 days) or placebo on glucose regulation was assessed in a randomized, double-blind, crossover study of young men and women (age 20-40 years and body mass index 18.5-27.5 kg/m ) without chronic disease, using 6-h oral glucose tolerance tests and continuous glucose monitoring.

RESULTS

Thirty-eight participants completed the study. Moxifloxacin prolonged the QTcF interval and increased heart rate. Hypoglycaemia was more frequently observed with moxifloxacin, both during the 8 days of continuous glucose monitoring and during the oral glucose tolerance tests. Hypoglycaemia questionnaire scores were higher after intake of moxifloxacin. Moxifloxacin reduced the early plasma-glucose response (AUC ) by 7% (95% CI: -9% to -4%, p < .01), and overall insulin response (AUC ) decreased by 18% (95% CI: -24% to -11%, p < .01) and plasma glucagon increased by 17% (95% CI: 4%-33%, p = .03). Insulin sensitivity calculated as the Matsuda index increased by 11%, and MISI, an index of muscle insulin sensitivity, increased by 34%.

CONCLUSIONS

In young men and women, moxifloxacin, a drug known to block the K 11.1 channel, increased QT interval, decreased glucose levels and was associated with increased muscle insulin sensitivity and more frequent episodes of hypoglycaemia.

© 2022 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.