Gentamicin and Cefasulbactum Do Not Cause Hypoglycemia
Neither gentamicin nor cefasulbactum (cefoperazone-sulbactam) are recognized causes of hypoglycemia in clinical practice or medical literature. These antibiotics do not interfere with glucose metabolism, insulin secretion, or insulin clearance through any known mechanism.
Evidence for Drug-Induced Hypoglycemia
The most comprehensive systematic review of drug-induced hypoglycemia identified 164 different drugs associated with hypoglycemia across 2,696 cases, but aminoglycosides (like gentamicin) and beta-lactam/beta-lactamase inhibitor combinations (like cefasulbactum) were not among them 1.
Antibiotics That DO Cause Hypoglycemia
Among antibacterial agents, only specific fluoroquinolones have well-documented associations with hypoglycemia 2, 1:
- Gatifloxacin is the most problematic fluoroquinolone, causing severe and resistant hypoglycemia, particularly when combined with sulfonylureas like glyburide 3, 4
- The mechanism involves gatifloxacin-induced closure of ATP-sensitive potassium channels in pancreatic beta cells, leading to excessive insulin secretion 3
- Hypoglycemia can occur even in non-diabetic patients with renal failure 4
Quinolones as a class were among the most commonly reported offending drugs in systematic reviews 1, but this primarily refers to gatifloxacin and to a lesser extent other fluoroquinolones—not aminoglycosides or cephalosporins.
Clinical Context: Actual Causes of Hypoglycemia to Consider
If your patient is experiencing hypoglycemia while on gentamicin or cefasulbactum, investigate these actual causes 5:
Diabetes Medications
- Insulin (highest risk, especially with renal impairment) 5
- Sulfonylureas (second-generation: glyburide, glipizide, glimepiride) 5
- Meglitinides (repaglinide, nateglinide) 5, 6
- Combination therapy with insulin secretagogues plus GLP-1 agonists or DPP-4 inhibitors 5
Renal Impairment
- Progressive kidney dysfunction increases hypoglycemia risk 5-fold in insulin-treated patients 5
- Reduced insulin clearance and impaired renal gluconeogenesis contribute 5
- Sulfonylureas and their active metabolites accumulate with declining GFR 5
Other Drug Classes Associated with Hypoglycemia
Common Pitfall
Do not attribute hypoglycemia to commonly used antibiotics like aminoglycosides or cephalosporins without evidence. This can lead to unnecessary discontinuation of appropriate antimicrobial therapy while missing the actual cause—most commonly diabetes medications, especially in the setting of acute illness, reduced oral intake, or worsening renal function 5.