[ANTIBIOTIC-ASSOCIATED ENCEPHALOPATHY]

Antibiotic-associated encephalopathy (AAE) is a relatively uncommon adverse drug event, mostly encountered in hospitalized patients undergoing intravenous antibiotic treatment. A typical case is reported and the literature is reviewed. Most antibiotic drugs have been implicated in the pathogenesis. Varied intriguing mechanisms may be involved, in particular, binding of β-lactams to GABA(A) receptors interfering with inhibitory neurotransmission and therefore enhancing bursts of excitatory neurons. Usually occurring within the first week of treatment commencement, AAE may present with myriad symptoms in different combinations that include impaired consciousness, agitation, hallucinations, delusions, seizures (often nonconvulsive), myoclonus, and cerebellar signs. Laboratory workup and neuroimaging are non-contributory, but EEG usually reveals triphasic waves, characteristic of encephalopathies, but nonspecific. Renal impairment is often an important risk factor, and high drug doses and prior brain disease are additional risk factors. Discontinuation of the offending drug is followed by resolution of the encephalopathy within a median of 5 days. Better awareness of the syndrome by clinicians will improve timely recognition and treatment of antibiotic-associated encephalopathy, which may be more frequently encountered with the increasing use of antibiotics.