Candidiasis and eryptococcosis are the most common fwigal diseases among patientssuffixhg from HIV infection. Amphotericin B, 5-fiuorocytosine and imidazole derivatives are thedrugs prescribed in such cases. The aim of the present work is to assess whether thecontemporaneous treatment of HIV-positive patients with combined therapies including reversetnmscriptase and proteinase inhiiitors could cause an interaction able to modify the Uierapeutic&ect of antirnycotic agents. Therefore an in vifro study to evaluate the antifimgal effect of antiretroviraiand antimycotic h g s association on yeasts growth was conducted. Methods: The strainsused for this study comprisai C.albicanr ( ~ 1 6a)n d C.neofonnam (n=16).Aii isolates were fkomclinicai specimens from HIV-seropositive subjects. Susceptibility tests of yeasts to amphotericin B,5-fluroqtosine, miwnazole and fluconazole, singuiarly and in association with saquinavir andazidovudine, were performeci according to the NCCLS method for agar dilution. The MIC dueswere obtained by applying the method of increasing scalar concentrations. To esthate theassociation inhibitory effect on yeasts growth, saquinavir and azidovudine were testkd respectively ata concentration of 18.75 pM.5 and 28 CLM/L, while the antimycotic agents were tested at subinhibitoryconcentrations. The FIC index used to estimate the interactions outcomes was alsocalculated. Results: The i n t d o n of saquinavir with al1 the antimycotic drugs caused on yeastsgrowth a synergy effect with potentiation (FIC indexc0.55) , addition (0.55<FIC index<l) andindifference effect (l<FIC index~2), w hereas azidovudine - antirnycotics association alwaysshowed an indifference effect. Antagonism was never obtained. Conclusion: The lack of antagonismindicates that the anti-retrovisal and antimycotic drugs association can be administrated withoutreducing the therapeutic antiibgai effects. The synergy shows that combined therapy could becaxried out using lower doses of antimycotic drugs, with a consequent reduction of toxic side effects.
In vitro interaction of Saquinavir and Azidovudine with some antimycotic drugs on human pathogen yeast / Casolari, Chiara; Rossi, Tiziana; Baggio, Giosuè Gabriele; Fabio, Giuliana; Ruberto, Ippazio Antonio; C., Farina; Castelli, Mario. - STAMPA. - unico:(2004), pp. F-019-F-019. (Intervento presentato al convegno 104th General Meeting American Society for Microbiology tenutosi a New Orleans nel NEW ORLEANS MAY 23-27).