Colistin-induced neurotoxicity in a young patient with multidrug-resistant Pseudomonas aeruginosa bacteremia: A case report

OBJECTIVE: (PA) bacteremia. CASE REPORT: ). As therapeutic drug monitoring (TDM) was unavailable, the CMS dose was reduced to 2 × 2.5 MIU based on cystatin C-estimated renal function, leading to resolution of neurological symptoms within 3 days. CMS was continued for 10 days, leading to improved inflammatory markers and clinical stabilization. CONCLUSION: Colistin-induced neurotoxicity should be considered in patients with new-onset neuropsychiatric symptoms, particularly in the setting of renal dysfunction or high cumulative exposure. Reliance on serum creatinine alone may misrepresent renal function; incorporation of cystatin C or urine clearance can improve dosing accuracy and reduce toxicity risk. When therapeutic alternatives are limited, dose reduction rather than discontinuation may be an appropriate strategy. Broader implementation of TDM is essential to optimize dosing and minimize adverse outcomes in clinical practice.