1832 ■ The Annals of Pharmacotherapy ■ 2010 November, Volume 44 theannals.com CASE REPORTS S taphylococcus aureus accounts for 1-9% of all cases of bacterial menin- gitis. 1 Appropriate selection and timely administration of antibiotics are critical for a patient with suspected bacterial meningitis. 2 Daptomycin is a cyclic lipo- peptide concentration-dependent antibi- otic that exerts its bactericidal activity by irreversibly binding within the bacterial cell membrane in a calcium-dependent process. 3 This leads to depolarization of the cell membrane and rapid cell death by inhibiting RNA, DNA, and protein synthesis. 4 Daptomycin is approved for treatment of skin and soft-tissue infec- tions and bacteremia, including right-sid- ed endocarditis caused by gram-positive bacteria, at recommended daily doses of 4 mg/kg and 6 mg/kg, respectively. 5 Its spectrum of coverage and bactericidal ac- tivity make daptomycin an acceptable al- ternative for methicillin-sensitive Staphy- lococcus aureus (MSSA) bacteremia and disseminated disease, such as meningitis, when traditional therapy fails or is con- traindicated secondary to relative toxici- ty or medication allergy. We present a case of documented MSSA bacteremia with suspected meningitis treated with Cerebrospinal Fluid Penetration of High-Dose Daptomycin in Suspected Staphylococcus aureus Meningitis M Shawn Riser, Christopher M Bland, Celeste N Rudisill, and P Brandon Bookstaver Author information provided at end of text. OBJECTIVE: To report a case of methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia with suspected MSSA meningitis treated with high-dose daptomycin assessed with concurrent serum and cerebrospinal fluid (CSF) concentrations. CASE SUMMARY: A 54-year-old male presented to the emergency department with generalized weakness and presumed health-care–associated pneumonia shown on chest radiograph. Treatment was empirically initiated with vancomycin, levofloxacin, and piperacillin/tazobactam. Blood cultures revealed S. aureus susceptible to oxacillin. Empiric antibiotic treatment was narrowed to nafcillin on day 4. On day 8, the patient developed acute renal failure (serum creatinine 1.9 mg/dL, increased from 1.2 mg/dL the previous day and 0.8 mg/dL on admission). The patient’s Glasgow Coma Score was 3, with normal findings shown on computed tomography scan of the head 72 hours following an episode of cardiac arrest on day 10. The patient experienced relapsing MSSA bacteremia on day 9, increasing the suspicion for a central nervous system (CNS) infection. Nafcillin was discontinued and daptomycin 9 mg/kg daily was initiated for suspected meningitis and was continued until the patient’s death on day 16. Daptomycin serum and CSF trough concentrations were 11.21 μg/mL and 0.52 μg/mL, respectively, prior to the third dose. Lumbar puncture results were inconclusive and no further blood cultures were positive for MSSA. Creatine kinase levels were normal prior to daptomycin therapy and were not reassessed. DISCUSSION: Daptomycin was initiated in our patient secondary to possible nafcillin-induced acute interstitial nephritis and relapsing bacteremia. At a dose of 9 mg/kg, resultant penetration of 5% was higher than in previous reports, more consistent with inflamed meninges. CONCLUSIONS: High-dose daptomycin may be an alternative option for MSSA bacteremia with or without a CNS source in patients who have failed or cannot tolerate standard therapy. Further clinical evaluation in patients with confirmed meningitis is warranted. KEY WORDS: bacteremia, daptomycin, meningitis, Staphylococcus aureus. Ann Pharmacother 2010;44:1832-5. Published Online, 19 Oct 2010, theannals.com, DOI 10.1345/aph.1P307 by guest on October 11, 2013 aop.sagepub.com Downloaded from by guest on October 11, 2013 aop.sagepub.com Downloaded from by guest on October 11, 2013 aop.sagepub.com Downloaded from by guest on October 11, 2013 aop.sagepub.com Downloaded from