- 医療薬学 (ISSN:1346342X)
- vol.27, no.2, pp.123-131, 2001-04-10 (Released:2011-03-04)
Although vancomycin has been exclusively used for methicillin-resistant Staphylococcus aureus (MRSA) therapy, there are many patients recently observed to suffer from gram negative bacteria, Pseudomonas aeruginosa as well as MRSA.Arbekacin (ABK), an aminoglycoside antibiotic (AG) is an alternative medication for such patients with those infection disease. However, it seems that the dosage of ABK used according to the manufacture's recommendations is insufficient for MRSA therapy to obtain a sufficient patient outcomes. Moreover, the relationship between the effectiveness of ABK on MRSA infection and the serum ABK concentration remains unclear. For the long-term treatment of AG, we can not rule out the possibility that AG may induce nephrotoxicity and ototoxicity.Therefore, the present study was carried out to clarify the significance of therapeutic drug monitoring (TDM) of ABK for patients with an MRSA infection, and elucidate the relationship between the serum ABK level and its clinical outcomes, including its antibacterial action and side effects. We investigated 30 patients with an MRSA infection, who received ABK at the Anjo Kosei Hospital from September 1996 to June 1998. The treatment of the patients by ABK but without TDM showed a 46.6% (7/15) therapeutic efficacy, while the patients with drug monitoring had a remarkably successful therapeutic efficacy (100% : 21/21) with a peak serum ABK concentration over 10μg/mL. Dysphagia badly affected the efficacy of ABK therapy in patients with an MRSA infection even when the serum ABK level was well-controlled. The incidence of ABK induced nephrotoxicity was observed in all patients when ABK was administered at a total dose of over 5, 000mg, while it was 4% at a total dose of less than 5, 000mg. When the duration of ABK therapy was longer than 2 weeks, the incidence of nephrotoxicity also significantly increased.These results thus suggest that TDM of ABK is useful for increasing the efficacy of ABK therapy in patients with an MRSA infection. In light of nephrotoxicity, these results indicate that ABK therapy may be completed within 2 weeks with an ABK dose of less than 5, 000mg, as the total dose.