Intrathecal administration of amikacin for treatment of meningitis secondary to cephalosporin-resistant Escherichia coli

Abstract

Objective: To report a case of gram-negative bacillary meningitis (GNBM) secondary to cephalosporin-resistant Escherichia coli that was treated with intrathecal and intravenous amikacin and intravenous imipenem/cilastatin (I/C).

Case summary: A patient who had undergone two recent neurosurgical procedures developed GNBM and bacteremia. He was treated empirically with ceftazidime. Both bloodstream and cerebrospinal fluid isolates were identified as E. coli, resistant to third-generation cephalosporins, penicillins, tobramycin, and gentamicin. The patient was subsequently treated with intravenous and intrathecal amikacin plus intravenous I/C. He experienced subjective and objective improvement on days 2-4 of antimicrobial therapy; two generalized tonic-clonic seizures occurred on days 7 and 12. Intrathecal amikacin was discontinued after 6 days, and intravenous amikacin and I/C were discontinued after 23 and 27 days, respectively. The patient's mental status did not completely return to premeningitis baseline.

Discussion: Third-generation cephalosporins are the treatment of choice for GNBM. In the case reported herein, bacterial resistance to these agents prompted the use of a therapy that has not been well studied and is also considered to be less safe and perhaps less efficacious. Treatment of GNBM with an intrathecally administered aminoglycoside or with intravenous I/C plus an aminoglycoside is reviewed.

Conclusions: Patients with GNBM secondary to third-generation cephalosporin-resistant organisms may require therapies that may be less effective and more toxic. Further study of alternative agents is warranted.