Fluconazole response patterns in HIV-infected patients with oropharyngeal candidiasis

Susceptibility profile of a Brazilian yeast stock collection of Candida species isolated from subjects with Candida-associated denture stomatitis with or without diabetes

OBJECTIVE

This study investigated the susceptibility of 198 clinical isolates of Candida species against caspofungin, amphotericin B, itraconazole, and fluconazole.

STUDY DESIGN

Suspensions of the microorganisms were spread on Roswell Park Memorial Institute (RPMI) agar plates. Etest strips were placed on the plates, and the minimal inhibitory concentration (MIC) was read after incubation (48 h at 37 °C). Data were analyzed by a factorial analysis of variance and a 2 × 2 post hoc test (α = .05).

RESULTS

C glabrata showed the highest MIC values (P < .001) against caspofungin, itraconazole, and fluconazole. For amphotericin B, the MIC values of C tropicalis and C glabrata (P = .0521) were higher than those of C albicans (P < .001). Itraconazole was the least effective antifungal; 93.3% of the C glabrata isolates, 3.3% of the C albicans, and 1.3% of the C tropicalis were resistant. All microorganisms were susceptible to caspofungin and amphotericin B.

CONCLUSIONS

Caspofungin and amphotericin B should be recommended as an effective alternative for the management of oral Candida infections when treatment with topical or other systemic drugs has definitely failed.

Comparative efficacy of topical therapy with a slow-release mucoadhesive buccal tablet containing miconazole nitrate versus systemic therapy with ketoconazole in HIV-positive patients with oropharyngeal candidiasis

This randomized comparative study assessed the efficacy and safety of a 10-mg once-daily topical regimen of miconazole nitrate mucoadhesive buccal tablet (n = 178) versus a 400-mg once-daily systemic regimen of ketoconazole (n = 179) in HIV-positive patients with oropharyngeal candidiasis. A total of 357 patients were treated for 7 or 14 days depending on response after 7 days of treatment. Clinical response was the primary outcome variable, and secondary outcomes included microscopy, time to cure, symptom scores, and safety outcomes. A per-protocol analysis of 332 patients demonstrated that miconazole nitrate was not statistically significantly inferior to ketoconazole treatment. At day 7, the clinical response rate was 135 of 156 (87%) for miconazole nitrate and 137 of 153 (90%) for ketoconazole (90% confidence interval of the treatment difference: [-9%; 3%]). At the end of treatment, dysphagia was 1% in both groups. Microscopic findings paralleled the clinical results. The mucoadhesive tablet was generally well tolerated. A higher incidence of gastrointestinal disorders and drug-related adverse events was seen during ketoconazole treatment. The low-dose 10-mg miconazole mucoadhesive tablet is not inferior to systemic antifungal treatment with ketoconazole in the treatment of AIDS-related oropharyngeal candidiasis with and without dysphagia. It provides the first and only once-daily topical treatment option and should therefore be considered in first-line therapy for this condition, particularly in resource-poor settings, where ease of use can help to guarantee the success of therapy.

Prevalence of fluconazole-resistant strains of Candida albicans in otherwise healthy outpatients

BACKGROUND

In contrast to the immunosuppressed patient population, the prevalence of fluconazole-resistant strains of Candida albicans among healthy individuals has not been extensively studied.

METHODS

Candida species were cultured form 50 healthy outpatients with clinical signs of oral candidiasis. Following one week of the recommended fluconazole regimen, post-treatment cultures were obtained. Both pre- and post-treatment yeasts were identified and in vitro susceptibility testing was performed using the NCCLS M-27A method. Strains were further differentiated using established cDNA probes.

RESULTS

Forty-four patients (88%) had positive C.albicans cultures prior to treatment. Antifungal susceptibility testing of these strains demonstrated no in vitro resistance to fluconazole. At post-treatment evaluation, eight patients (18%) had persistent signs of infection and 10 patients (23%) had positive Candida sp. cultures despite no clinical signs of infection. DNA analysis confirmed that the same C. albicans strain was present both in the pre-treatment and the post-treatment cultures.

CONCLUSIONS

Our results showed that the presence of fluconazole-resistant strains of C.albicans does not appear to be prevalent among healthy outpatients furthermore, in vitro antifungal susceptibility testing does not always predict successful therapy in these patients.

Safety and efficacy of single-dose fluconazole compared with a 7-day regimen of itraconazole in the treatment of AIDS-related oropharyngeal candidiasis

The primary aim of this study was to compare the efficacy and safety of single-dose fluconazole and a 7-day regimen of itraconazole for the treatment of oropharyngeal candidiasis in human immunodeficiency virus (HIV)-positive patients. In this open-label trial, 40 HIV-positive patients with oropharyngeal candidiasis were randomized to receive either one dose of fluconazole 150 mg or seven daily doses of itraconazole 100 mg. Clinical condition was assessed at baseline, day 8, and day 30 (follow-up). In the fluconazole group, 15 of 20 (75%) patients were clinically cured on day 8, three (15%) were clinically improved, and two (10%) were treatment failures. At follow-up, six (30%) patients experienced relapse. In the itraconazole group, four of 17 (24%) patients were clinically cured at 8 days, and two (12%) were clinically improved; two patients relapsed by day 30. Ten (50%) patients in the itraconazole group were taking concomitant medications that could potentially affect the bioavailability of itraconazole. After excluding the results from these patients, clinical response rates remained significantly higher in the fluconazole treatment arm. These results suggest that a single 150-mg dose of fluconazole may be a safe, effective, and convenient therapy for acquired immune deficiency syndrome-related oropharyngeal candidiasis. The lower response rate in the patients who received itraconazole 100 mg daily for 7 days could be explained by drug interactions and the unpredictable absorption of itraconazole.

Fluconazole-resistant Candida species in the oral flora of fluconazole-exposed HIV-positive patients

The purpose of this study was to examine the effect of preceding fluconazole treatment on the oral mycologic flora and on the sensitivity of oral Candida albicans isolates to fluconazole. Saline oral rinses were collected from 89 HIV-positive patients, of whom 48 had been exposed to fluconazole and 41 were fluconazole-naive. The rinses were cultured on Sabouraud's and Pagano Levin agars, and yeasts were identified by standard methods. Fluconazole sensitivity of C. albicans isolates was measured by disk diffusion assay. C. albicans was isolated from 69% of patients who had received fluconazole and from 93% of the patients who were fluconazole-naive (p < 0.05). Nine other species of yeasts were also isolated, most commonly C. glabrata. Five patients previously exposed to fluconazole harbored fluconazole-resistant C. albicans, whereas no resistance was detected among the patients who were fluconazole-naive (p < 0.01). Sixteen of the patients who were fluconazole-exposed carried yeasts other than C. albicans, compared with only five patients in the fluconazole-naive group (p < 0.01). All of the fluconazole-resistant strains were isolated from patients with low CD4 counts (less than 100 cells/ml) and after lengthy fluconazole exposures. Nevertheless, patients in Charlotte, N.C., who had a greater mean fluconazole exposure time (10.25 +/- 1.41 months) than patients in Glasgow, UK, (0.65 +/- 0.18 months; p < 0.005), did not develop significantly more in vitro resistance or species diversity. This study indicates that long-term fluconazole treatment can have significant effects on the yeast flora of the mouth, particularly in a patient with a CD4 count of less than 100 cells/ml.

Clinical characteristics and management responses in 85 HIV-infected patients with oral candidiasis

Eighty-five consecutively seen HIV-positive persons with oral candidiasis were evaluated for clinical characteristics, staging of HIV disease, quantitation of candidal colony formation, and response to systemic antifungal treatment with Nizoral (ketoconazole). Fifty-five had CD4 counts less than 200. There was an inconsistent association between clinical signs, patient symptoms, CD4 counts, and candidal colony-forming units. However, there was a trend toward higher colony-forming unit counts (> 500) in patients with lower CD4 cells (< 200). Sixty-five patients had a complete clinical response to the ketoconazole treatment (200 mg daily for 7 days), even though 81% of posttreatment cultures remained positive. Nonsmokers were more likely to respond to antifungal treatment when compared with smokers, and there was a slight tendency for complete responses when colony-forming unit counts were low. The most common lesion presentation was a combination of the white (pseudomembranous) and red (erythematous) forms. Forty-nine percent had complaints of pain. The variable responses indicated the importance of flexible dose-time and drug considerations in antifungal management. Candida albicans was the predominant species.