Potential Role of Therapeutic Drug Monitoring in Preventing Antibiotic-Induced Neuropsychiatric Disorders: A Narrative Review

Background: Neuropsychiatric toxicity is a common adverse effect of antibiotics. Advanced age, renal insufficiency, high drug doses, and prolonged therapy are relevant risk factors, suggesting that this event might be caused due to the accumulation of antibiotics in the central nervous system. In this review, the authors aimed to evaluate the potential role of therapeutic drug monitoring in identifying patients at risk of antibiotic-induced neuropsychiatric toxicity. Methods: A MEDLINE PubMed search was conducted for articles published between January 1990 and December 2024, matching the terms “pharmacokinetics” or “therapeutic drug monitoring” with “antibiotics” (including individual drug classes) and “neurotoxicity” (including synonyms). Additional studies were identified from the reference lists of retrieved articles. Results: Significant associations have been reported between plasma concentrations of some beta-lactam antibiotics (ceftazidime, cefepime, piperacillin, and meropenem) or linezolid and drug-induced central nervous system adverse events (such as seizures, encephalopathy, peripheral neuropathy, and optic neuropathy). Safety thresholds of plasma concentrations have been proposed for these drugs. Conclusions: Consistent data on the associations between plasma drug concentrations and neuropsychiatric disorders are available only for some antibiotics, whereas for others, there are few and often inconsistent data, hindering the establishment of therapeutic drug monitoring-based safety thresholds for these antibiotics.