Therapeutic drug monitoring of intravenous amikacin during peritoneal dialysis for Mycobacterium abscessus exit-site infection: a case report

Patients with peritoneal dialysis (PD) often develop exit-site infections (ESI) caused by nontuberculous mycobacteria. Antimicrobial therapy, including intravenous amikacin (AMK), is combined with PD catheter removal to control the source of infection. However, the efficiency of AMK removal using PD remains unclear. In this report, we describe AMK pharmacokinetics before and after PD catheter removal in a patient diagnosed with Mycobacterium abscessus from ESI.

A 73-year-old female PD patient weighing 42.4 kg who received intravenous AMK + clarithromycin + imipenem/cilastatin for Mycobacterium abscessus ESI on day 1 under therapeutic drug monitoring. During hospitalization, the patient underwent a typical PD regimen including nocturnal continuous ambulatory PD with Reguneal HCa 1.5^® (1.5% glucose) 1.5 L (2-hour storage) + Reguneal HCa 1.5^® 1.5 L or Extraneal^® (7.5% icodextrin) 1.5 L (11.5-hour storage). Dosing schedule of AMK was 200 mg every 48 h to maintain an AMK trough concentration around 10 µg/mL. On day 14, the PD catheter was removed and reinserted on the contralateral side for source control of the infection site and PD was discontinued until day 20. The elimination rate constant (Ke) of AMK was 0.027 h^− 1 obtained from peak concentration (C_peak) of 16.3 µg/mL on day 1 and trough concentration (C_trough) of 4.5 µg/mL on day 3. In contrast, Ke was 0.020 h^− 1 calculated from both C_peak of 22.2 µg/mL on day 9 and C_trough of 8.4 µg/mL on day 11, as well as C_peak of 23.8 µg/mL on day 17 and C_trough was 9.3 µg/mL on day 19. Combination antibiotic therapy was completed due to clinical improvement on day 27. Post-treatment, clofazimine and clarithromycin were administered orally, and the patient was discharged on day 32.

The effect of PD on AMK concentration was limited during therapeutic drug monitoring.