OBJECTIVES

Cefiderocol has emerged as a key treatment for managing MDR infections, and its time-dependent pharmacodynamics are optimized by prolonged infusion to maintain time above the MIC ( ). Whereas recent stability studies have shown cefiderocol remains stable up to 72 h in elastomeric pumps, its use in 24 h continuous infusions (CIs) for outpatient parenteral antibiotic therapy (OPAT) is undocumented. This case highlights its suitability for 24 h CI via elastomeric pumps in an OPAT setting, supported by therapeutic drug monitoring (TDM) to ensure optimal treatment efficacy.

PATIENT/CASE DESCRIPTION: A 31-year-old male developed right-sided otomastoiditis caused by producing New Delhi MBL (NDM). Given the resistance profile and the need for prolonged therapy, cefiderocol was initiated at a daily dose of 6 g, administered by 24 h CI using an elastomeric pump. TDM was performed on Days 17 and 45 to assess plasma concentrations.

RESULTS

TDM confirmed steady-state concentrations ( 25.2-28.1 mg/L), achieving optimal pharmacokinetic/pharmacodynamic (PK/PD) target attainment such as 100% (free [] /MIC 10.58-11.80). Significant clinical improvement avoided the need for planned surgery, with no adverse events reported from the venous catheter, antibiotic therapy or elastomeric pump.

CONCLUSIONS

This approach underscores the feasibility and efficacy of cefiderocol administered by 24 h CI by means of an elastomeric pump and supported by real-time TDM in achieving an aggressive PK/PD target for the treatment of otomastoiditis due to NDM-producing .