Effect of inhaled vancomycin hydrochloride on elimination of methicillin-resistant Staphylococcus aureus

Vancomycin hydrochloride (VCM) is one of the most useful drugs in treating methicillin-resistant Staphylococcus aureus (MRSA) infections. Intravenous administration of the drug is, however, not appropriate in patients with impaired renal or liver function. Thus, we studied the effect of inhaled VCM on MRSA. Fifty-one patients with MRSA in their sputum (35 men and 16 women 21, in the "infected" group and 30 in the "colonized" group, mean age 76.4 years) were studied. MRSA was eliminated in 84.3% of the patients (43 of 51 patients), and the average time required for elimination was 14.7 days. MRSA colonization or infection recurred in 46.5% of the patients (20 of 43 patients), and the duration from elimination until recurrence of MRSA averaged 28 days. Eight patients in whom MRSA was not eliminated by inhaled VCM were not clinically distinguishable from other patients, but their performance status was worse. Two hours after VCM was inhaled, serum VCM concentrations were unmeasurable in 7 patients. The VCM level in sputum peaked at 262.5 micrograms/g just after inhalation, and then gradually decreased. No side effects of this treatment were observed. These results suggest that inhaled VCM can be used to eliminate MRSA.