Nontraditional dosing of ampicillin-sulbactam for multidrug-resistant Acinetobacter baumannii meningitis

A 52-year-old man was admitted to a local hospital with headache, nausea, vomiting, dizziness, photophobia, and confusion after a sudden fall. Progressive changes in neurologic function were noted despite neurosurgical intervention and broad-spectrum antimicrobial coverage. Cerebral spinal fluid (CSF) culture identified Acinetobacter baumannii that was resistant to traditionally recommended therapies of amikacin and imipenem-cilastatin. The organism demonstrated minimum inhibitory concentrations of greater than 32 microg/ml and 8 microg/ml, respectively, for these two agents. Ampicillin 2 g-sulbactam 1 g every 3 hours was administered based on history of therapeutic failure of traditional dosing in our thermal injury population. Repeat CSF cultures after 12 days of ampicillin-sulbactam therapy were negative. After 35 days, the patient's A. baumannii infection was completely resolved. The patient experienced no adverse drug events or toxicity with this high-dosage regimen.