Objective:

To describe recurrent endogenous ethanol intoxication in a patient with known auto-brewery syndrome (ABS) after antibiotic exposure.

Approach:

• Case presentation: A man in his mid-40s with known ABS was found unresponsive five days after starting amoxicillin/clavulanate for pneumonia, following about two symptom-free years.
• Clinical assessment and care: His Glasgow Coma Scale score was 9 and blood alcohol concentration was 43.6 mmol/L despite reported abstinence. Imaging and arterial blood gas results were unremarkable; naloxone and flumazenil had no effect. He received supportive intensive care, and the anti…
• Relevant history: Earlier evaluation found small intestinal bacterial overgrowth and increased Proteobacteria, predominantly Enterobacter species. Rifaximin and probiotics were followed by approximately two years without symptoms.

Key Findings:

• The patient recovered within hours after rehydration and was discharged with a Glasgow Coma Scale score of 15 and no neurologic deficits.
• The clinical team attributed the episode to endogenous ethanol intoxication from ABS and proposed that antibiotic-associated microbiome disruption may have contributed.
• The authors cited prior case reports in which antibiotic exposure preceded symptoms in 7 of 16 ABS cases.

Interpretation:

The authors considered the timing of antibiotic exposure and the patient's history consistent with a possible role for antibiotic-induced dysbiosis, but the case does not establish causation. They stated that ABS should be considered in otherwise unexplained intoxication when reported abstinence is credible and advised caution with antibiotic therapy in patients with known ABS.

Limitations:

• Single-patient case design; causation by amoxicillin/clavulanate cannot be established.
• Interpretation was complicated by previous alcohol overuse, small intestinal bacterial overgrowth, altered gut microbiota, and ABS episodes predating the recent antibiotic exposure.

Conclusion:

The authors reported no conflicts of interest or funding.

Sources:

• Oxford Medical Case Reports