Antibiotic precedes auto-brewery relapse

A patient developed severe endogenous alcohol intoxication 5 days after starting treatment following approximately 2 years without symptoms.

By
Andrea Surnit
October 8, 2026
3 min

MDSpire News

At a Glance

Category	Detail
Condition	Auto-brewery syndrome (ABS), with recurrent endogenous ethanol intoxication after recent antibiotic exposure in one reported patient
Key Mechanisms	The authors hypothesized that antibiotic-associated disruption of the gut microbiome may have contributed to recurrence. ABS has been associated with ethanol-producing yeasts, and the authors noted evidence that bacteria may also contribute to endogenous ethanol production.
Target Population	The report concerns a man with known ABS; the authors suggested considering ABS when alcohol intoxication is otherwise unexplained and reported abstinence is credible.
Care Setting	Emergency department and intensive care evaluation of a single patient in Switzerland.

Key Highlights

A man with known ABS developed severe intoxication five days after starting amoxicillin/clavulanate for community-acquired pneumonia, following about two years without symptoms.
His blood alcohol concentration was 43.6 mmol/L despite reported abstinence; cranial CT showed no hemorrhage or structural brain damage, and arterial blood gas results were within normal limits.
He received supportive intensive care, amoxicillin/clavulanate was discontinued, and he recovered within hours after rehydration.
The authors considered antibiotic-associated dysbiosis a possible contributor, but the single-patient report cannot establish that the antibiotic caused the relapse.
The authors advised considering ABS in otherwise unexplained intoxication when reported abstinence is credible and approaching antibiotic therapy cautiously in patients with known ABS.

Guideline-Based Recommendations

Diagnosis

The authors advised considering ABS in otherwise unexplained alcohol intoxication when reported abstinence is credible.
In this case, evaluation included blood alcohol measurement, arterial blood gas testing, cranial CT, and empiric naloxone and flumazenil, which produced no clinical improvement.

Management

In this case, the patient received supportive intensive care, rehydration, and discontinuation of amoxicillin/clavulanate.
The authors advised caution with antibiotic therapy in patients with known ABS, considering possible relapse.

Monitoring & Follow-up

The report describes monitoring during supportive care. The patient recovered within hours and was discharged with a Glasgow Coma Scale score of 15 and no neurologic deficits.

Risks

The authors proposed antibiotic-associated dysbiosis as a possible contributor to recurrence, based on the timing and the patient's history.
The single-patient case cannot establish causation. Previous alcohol overuse, small intestinal bacterial overgrowth, altered gut microbiota, and earlier ABS episodes complicate interpretation.

Patient & Prescribing Data

A man in his mid-40s with known ABS and a history of small intestinal bacterial overgrowth and altered gut microbiota.

After starting amoxicillin/clavulanate for community-acquired pneumonia, he developed recurrent endogenous ethanol intoxication. The antibiotic was discontinued and supportive care and rehydration were provided. Earlier, a 14-day course of rifaximin and probiotics was followed by approximately two years without ABS symptoms.

Clinical Best Practices

Include ABS in the differential diagnosis of otherwise unexplained alcohol intoxication when abstinence is credibly reported.
For patients with known ABS, consider the authors' caution regarding antibiotic therapy and possible relapse.
Interpret the proposed antibiotic–dysbiosis relationship as a hypothesis from a single case, not established causation.