Antibiotic-Induced Manic Episodes: Clinical Recognition, Mechanistic Pathways, and Management.

Abstract

Antibiotic-induced manic episodes describe the emergence of manic or hypomanic symptoms during or shortly after antimicrobial therapy. Although uncommon, these reactions are clinically important because they may be misattributed to primary bipolar disorder, delirium, or neuropsychiatric effects of infection. Hence, the objective of this study was to synthesize the evidence on antibiotic-induced manic episodes, with emphasis on clinical recognition, plausible mechanisms, management, and verified sequential citations. A targeted narrative review and reference-verification process was conducted using PubMed/MEDLINE, Google Scholar, publisher webpages, Crossref/DOI records when available, and regulatory safety communications. Searches and source checks were updated through March 2026. Findings were synthesized narratively because the evidence base is mainly case reports, pharmacovigilance data, and reviews. The literature is dominated by case reports, pharmacovigilance analyses, and systematic or narrative reviews. Prospective denominator-based incidence studies remain lacking. Macrolides, particularly clarithromycin, fluoroquinolones, and antitubercular drugs, account for many published cases. Doxycycline and beta-lactam combinations are also represented in recent reports. Onset is commonly rapid, often within days, and may include insomnia, pressured speech, increased activity, irritability or euphoria, grandiosity, and psychotic symptoms. Most cases improve after the discontinuation of the suspected antibiotic. Severe presentations may require short-term antipsychotic or benzodiazepine treatment. Proposed mechanisms include reduced GABAergic inhibition, monoaminergic effects, including monoamine oxidase-related pathways, CYP3A4-mediated drug interactions, mitochondrial and oxidative stress pathways, and gut-brain axis disruption. Antibiotic-induced manic episodes should be considered when new manic or psychotic symptoms arise during, or soon after, antibiotic therapy. Management requires prompt medication review, discontinuation or substitution of the suspected agent when clinically feasible, short-term symptomatic psychiatric treatment when indicated, and pharmacovigilance reporting.