Effects of dosing regimen on accumulation, retention and prophylactic efficacy of liposomal amphotericin B.
J Antimicrob Chemother
; 59(5): 941-51, 2007 May.
Article
em En
| MEDLINE
| ID: mdl-17400589
ABSTRACT
OBJECTIVES:
We hypothesized that effective prophylactic treatment of fungal infections would require adequate drug penetration and retention at potential infection sites. Using a mouse model, we examined liposomal amphotericin B (L-AmB) biodistribution, cell localization and retention in kidneys, lungs, liver and spleen to evaluate effective dosing regimens for prophylaxis of Candida glabrata and Candida albicans infections.METHODS:
Following treatment of mice with cumulative doses of L-AmB (60-225 mg/kg), a bioassay was done to determine tissue drug concentrations 12 h to 6 weeks post-treatment. Immunohistochemical staining with anti-amphotericin B antibodies was used for cellular drug localization. Mice were treated prophylactically with 15-90 mg/kg L-AmB and challenged intravenously 1-7 days later with C. glabrata or they were given a total of 60 mg/kg as daily or intermittent dosing followed by intravenous challenge with C. albicans 3 or 6 weeks later.RESULTS:
On the basis of microg/g tissue, the relative amount of drug was in the order spleen > liver > kidneys > lungs. Amphotericin B levels were maintained above the MIC for many fungi for 1 week in lungs and for as long as 6 weeks in kidneys and spleen. Drug localized in kidney tubular epithelial cells and in macrophages of liver and spleen. In prophylactic models, fungal burden was reduced by several 1000-fold or was undetectable within target tissues (kidneys, spleen).CONCLUSIONS:
These observations underscore the importance of including drug tissue levels to obtain a better understanding of L-AmB efficacy. The sustained concentrations of bioactive AmB in many tissues provide a further rationale for investigating L-AmB prophylactic regimens.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Candida albicans
/
Candidíase
/
Anfotericina B
/
Antibioticoprofilaxia
/
Candida glabrata
/
Antifúngicos
Limite:
Animals
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article