Treatment of refractory oral candidiasis with fluconazole. A case report

Fluconazole-Loaded Ibuprofen In Situ Gel-Based Oral Spray for Oropharyngeal Candidiasis Treatment

Oral candidiasis is a fungal infection affecting the oral mucous membrane, and this research specifically addresses on a localized treatment through fluconazole-loaded ibuprofen in situ gel-based oral spray. The low solubility of ibuprofen is advantageous for forming a gel when exposed to an aqueous phase. The 1% w/w fluconazole-loaded in situ gel oral sprays were developed utilizing various concentrations of ibuprofen in N-methyl pyrrolidone. The prepared solutions underwent evaluation for viscosity, surface tension, contact angle, water tolerance, gel formation, interface interaction, drug permeation, and antimicrobial studies. The higher amount of ibuprofen reduced the surface tension and retarded solvent exchange. The use of 50% ibuprofen as a gelling agent demonstrated prolonged drug permeation for up to 24 h. The incorporation of Cremophor EL in the formulations resulted in increased drug permeation and exhibited effective inhibition against Candida albicans, Candida krusei, Candida lusitaniae, and Candida tropicalis. While the Cremophor EL-loaded formulation did not exhibit enhanced antifungal effects on agar media, its ability to facilitate the permeation of fluconazole and ibuprofen suggested potential efficacy in countering Candida invasion in the oral mucosa. Moreover, these formulations demonstrated significant thermal inhibition of protein denaturation in egg albumin, indicating anti-inflammatory properties. Consequently, the fluconazole-loaded ibuprofen in situ gel-based oral spray presents itself as a promising dosage form for oropharyngeal candidiasis treatment.

The Dysbiosis and Inter-Kingdom Synergy Model in Oropharyngeal Candidiasis, a New Perspective in Pathogenesis

As more information emerges on oral microbiota using advanced sequencing methodologies, it is imperative to examine how organisms modulate the capacity of each other to colonize or trigger infection. Most mouse models of oral C. albicans infection have focused on interactions with single bacterial species. Thus, little is known about the microbiome-mediated interactions that control the switch of C. albicans from commensalism to infection. Evidence is accumulating that in immunosuppression where mucosal candidiasis is more prevalent, there is an altered oral bacterial microbiome with reduced diversity, but not an altered mycobiome. Oropharyngeal candidiasis in immunosuppressed humans and mice is associated with a further reduction in oral bacterial diversity and a dysbiotic shift with significant enrichment of streptococcal and enterococcal species. Our recent studies in a cancer chemotherapy mouse model supported the combined profound effect of immunosuppression and C. albicans in reducing oral bacterial diversity and provided the first direct evidence that these changes contribute to pathogenesis, representing dysbiosis. There is still a gap in understanding the relationship between Candida and the oral bacterial microbiome. We propose that certain oral commensal bacteria contribute to fungal pathogenesis and we identify gaps in our understanding of the mechanisms involved in this cooperative virulence.

The Relationship of Candida albicans with the Oral Bacterial Microbiome in Health and Disease

Candida albicans is an opportunistic pathogen colonizing the oropharyngeal, esophageal, and gastrointestinal mucosa in most healthy humans. In immunocompromised hosts, this fungal organism can cause mucosal candidiasis in these sites. C. albicans also causes fungemia, a serious consequence of cancer cytotoxic chemotherapy, which is thought to develop from fungal translocation through compromised mucosal barriers. Changes in endogenous bacterial population size or composition as well as changes in the host environment can transform fungal commensals into opportunistic pathogens in the upper and lower GI tract. Pioneering studies from our group have shown that a ubiquitous oral commensal of the mitis streptococcal group (Streptococcus oralis) has a mutualistic relationship with C. albicans, with C. albicans enabling streptococcal biofilm growth at mucosal sites, and S. oralis facilitating invasion of the oral and esophageal mucosa by C. albicans. In these studies, we used a cortisone-induced immunosuppression mouse model. More recently, the development of a novel mouse chemotherapy model has allowed us to examine the interactions of C. albicans with the endogenous bacterial microbiota in the oral and small intestinal mucosa, two sites adversely affected by cytotoxic chemotherapy. In this model, oral inoculation with C. albicans causes severe dysbiosis in the mucosal bacterial composition in both sites. We also found that antibiotic treatment ameliorates invasion of the oral mucosa but aggravates dissemination through the intestinal mucosa. In this chapter, we discuss work from our laboratory and others examining the relationships of C. albicans with oral bacteria and their role in mucosal homeostasis or disease.

Oral candidal infections and antimycotics

The advent of the human immunodeficiency virus infection and the increasing prevalence of compromised individuals in the community due to modern therapeutic advances have resulted in a resurgence of opportunistic infections, including oral candidoses. One form of the latter presents classically as a white lesion of "thrush" and is usually easily diagnosed and cured. Nonetheless, a minority of these lesions appears in new guises such as erythematous candidosis, thereby confounding the unwary clinician and complicating its management. Despite the availability of several effective antimycotics for the treatment of oral candidoses, failure of therapy is not uncommon due to the unique environment of the oral cavity, where the flushing effect of saliva and the cleansing action of the oral musculature tend to reduce the drug concentration to sub-therapeutic levels. This problem has been partly circumvented by the introduction of the triazole agents, which initially appeared to be highly effective. However, an alarming increase of organisms resistant to the triazoles has been reported recently. In this review, an overview of clinical manifestations of oral candidoses and recent advances in antimycotic therapy is given, together with newer concepts, such as the post-antifungal effect (PAFE) and its possible therapeutic implications.

Emergence of resistance of Candida albicans to clotrimazole in human immunodeficiency virus-infected children: in vitro and clinical correlations

Oropharyngeal candidiasis (OPC) is a common opportunistic infection in human immunodeficiency virus (HIV)-infected patients and other immunocompromised hosts. Clotrimazole troches are widely used in the treatment of mucosal candidiasis. However, little is known about the potential contribution of clotrimazole resistance to the development of refractory mucosal candidiasis. We therefore investigated the potential emergence of resistance to clotrimazole in a prospectively monitored HIV-infected pediatric population receiving this azole. Adapting the National Committee for Clinical Laboratory Standards M27-A reference method for broth antifungal susceptibility testing of yeasts to clotrimazole, we compared MICs in macrodilution and microdilution assays. We further analyzed the correlation between these in vitro findings and the clinical response to antifungal therapy. One isolate from each of 87 HIV-infected children was studied by the macrodilution and microdilution methods. Two inoculum sizes were tested by the macrodilution method (10(3) and 10(4) CFU/ml) in order to assess the effect of inoculum size on clotrimazole MICs. The same isolates also were tested using a noncolorimetric microdilution method. Clotrimazole concentrations ranged from 0.03 to 16 microg/ml. Readings were performed after incubation for 24 and 48 h at 35 degrees C. For 62 (71.2%) of 87 clinical isolates, the MICs were low (< or =0.06 microg/ml). The MIC for 90% of the strains tested was 0.5 microg/ml, and the highest MIC was 8 microg/ml. There was no significant difference between MICs at the two inoculum sizes. There was 89% agreement (+/-1 tube) between the microdilution method at 24 h and the macrodilution method at 48 h. If the MIC of clotrimazole for an isolate of C. albicans was > or =0.5 microg/ml, there was a significant risk (P < 0.001) of cross-resistance to other azoles: fluconazole, > or = 8 microg/ml (relative risk [RR] = 8.9); itraconazole, > or =1 microg/ml (RR = 10). Resistance to clotrimazole was highly associated with clinically overt failure of antifungal azole therapy. Six (40%) of 15 patients for whom the clotrimazole MIC was > or =0.5 microg/ml required amphotericin B for refractory mucosal candidiasis versus 4 (5.5%) of 72 for whom the MIC was <0.5 microg/ml (P = 0.001; 95% confidence interval = 2.3 to 22; RR = 7.2). These findings suggest that an interpretive breakpoint of 0.5 microg/ml may be useful in defining clotrimazole resistance in C. albicans. The clinical laboratory's ability to determine MICs of clotrimazole may help to distinguish microbiologic resistance from the other causes of refractory OPC, possibly reducing the usage of systemic antifungal agents. We conclude that resistance to clotrimazole develops in isolates of C. albicans from HIV-infected children, that cross-resistance to other azoles may develop concomitantly, and that this resistance correlates with refractory mucosal candidiasis.

Oropharyngeal candidiasis: a review of its clinical spectrum and current therapies

With the increased use of antibiotics and immunosuppressive agents, oropharyngeal candidiasis is becoming more common. This infection is also associated with such advances in medical management as chemotherapy and organ transplantation and with human immunodeficiency virus infection. Various topical and systemic agents are available to treat patients with candidiasis, but optimal management can be elusive. Treatment of uncomplicated oropharyngeal candidiasis in the immunocompetent patient involves selecting a particular formulation of a topical medication based on oral conditions, length of contact time, and taste, texture, and cost of the medication. Treatment of severe oropharyngeal candidiasis, particularly in patients with a compromised immune system, is often more difficult, and relapses are common. Reports of resistance to systemic agents, particularly in patients needing recurrent therapy, are increasing. Amphotericin B, long used as an intravenous agent, is now available as an oral suspension that may offer therapeutic benefits comparable to those of systemic therapy without the toxicity associated with systemic absorption.

Stable azole drug resistance associated with a substrain of Candida albicans from an HIV-infected patient

Oral candidiasis is one of the earliest and most frequent complications of a failing immune system in HIV-infected individuals. For several years, oral candidiasis has been treated effectively with azole drugs, the one most frequently used is fluconazole. Unfortunately, extensive use of the drug for treatment and prophylaxis has led to treatment failure in an increasing number of patients. In most of these cases, strains of C. albicans isolated from the infection are less susceptible to fluconazole. The development of azole resistance in strains of C. albicans has been studied biochemically and more recently with molecular techniques. One excellent example of the development of azole resistance in C. albicans has been documented in a series of 17 C. albicans isolates from a single patient over a 2-year period. During this time, the patient experienced 14 episodes of oral candidiasis and was treated with increasing doses of fluconazole. Molecular and biochemical analyses confirms that the isolates are the same strain of C. albicans and that the resistance in these isolates is stable over 600 generations, suggesting that the changes in this strain are genetic in nature. In addition, the development of resistance is correlated with the identification of a substrain or variant of the original strain, as identified by restriction fragment length polymorphism (RFLP) analysis with the moderately repetitive probe, Ca3. The analysis of this series of isolates demonstrates that azole drug resistance is associated with several small genetic changes, each of which contributes to the overall resistance of the strain. Clearly, continual use of azole drugs by a patient can select for genetic changes that render oral candidiasis refractory to treatment.

Comparison of different treatment methods for localized and generalized simple denture stomatitis

The purpose of this study was to compare the treatment effects of fluconazole, fluconazole plus chlorhexidine and the fitting of new dentures upon the treatment of denture stomatitis and 15 subjects with clinical evidence of localized simple denture stomatitis were investigated clinically and mycologically. Patients with clinical evidence of generalized simple denture stomatitis were divided into three treatment groups. The first group was given 50 mg of fluconazole tablets daily for 2 weeks. The second group were instructed to apply chlorhexidine solution to the inner surface of the denture twice a day in addition to fluconazole treatment for 2 weeks. New dentures were constructed for the third group. Patients with clinical evidence of localized simple denture stomatitis were fitted new dentures without antifungal therapy. Palatal swabs were taken from each subject before, immediately after, and 2 weeks after the end of treatment, and the samples were examined mycologically in order to identify yeast colonies. It was found that for generalized simple denture stomatitis, treatment with fluconazole plus chlorhexidine resulted in better improvement of palatal inflammation than that by either fluconazole or the fitting of new dentures without medication. Whereas fitting new dentures did not reduce inflammation in patients with generalized simple denture stomatitis, the beneficial effects of prosthetic treatment were seen in patients with localized simple denture stomatitis.

Salivary concentrations of ketoconazole and fluconazole: implications for drug efficacy in oropharyngeal and esophageal candidiasis

OBJECTIVE

To determine whether salivary concentrations of ketoconazole and fluconazole may explain the apparent disparity between in vitro activity and clinical efficacy observed with these drugs.

DESIGN

Healthy subjects received a single oral dose of ketoconazole 400 mg or fluconazole 100 mg in a randomized, crossover fashion. Saliva was collected at 0, 1, 2, 3, 6, 12, and 24 hours. Blood samples were obtained at 2 and 24 hours. Salivary concentrations and plasma concentrations for each drug were determined by HPLC. Minimum inhibitory concentration (MIC) testing was determined in triplicate on 6 clinical isolates of Candida albicans, and times over the median MIC values were calculated.

PARTICIPANTS

Eight subjects completed the study.

RESULTS

The mean (+/- SD) peak salivary concentration for ketoconazole was 0.119 +/- 0.050 microgram/mL at 3 hours; no subject had a detectable ketoconazole salivary concentration at 24 hours. At 2 and 24 hours, mean ketoconazole plasma concentrations were 7.64 +/- 3.87 and 0.11 +/- 0.05 microgram/mL, respectively. The saliva to plasma concentration ratio at 2 hours was 0.01. The mean peak salivary concentration of fluconazole was 2.56 +/- 0.34 microgram/mL at 3 hours. At 24 hours, the mean salivary concentration was 1.44 +/- 0.33 microgram/mL. At 2 and 24 hours, mean fluconazole plasma concentrations were 4.39 +/- 3.33 and 3.72 +/- 2.83 micrograms/mL, respectively. The saliva to plasma concentration ratio at 2 hours was 0.55. Median MIC values were 0.0625 microgram/mL (range 0.0313-0.125) for ketoconazole and 0.25 microgram/mL (range 0.125-0.5) for fluconazole. Calculated times over which ketoconazole and fluconazole exceeded the median MICs in saliva were approximately 13 and greater than 24 hours, respectively.

CONCLUSIONS

After a single oral dose, fluconazole achieved higher salivary concentrations than did ketoconazole. This may explain the increased clinical efficacy of fluconazole in the treatment of oropharyngeal-esophageal candidiasis when compared with ketoconazole.

Comparison of three different treatment methods for generalized denture stomatitis

This study compared the effects of fluconazole, fluconazole plus chlorhexidine, and placing new dentures for the treatment of generalized simple denture stomatitis. Subjects with clinical evidence of generalized simple denture stomatitis were investigated clinically and myocologically. These 45 patients were divided into three groups. The first group was given 50 mg of fluconazole in tablet form once a day for 2 weeks. The second groups were instructed to apply chlorhexidine solution to the inner surface of the denture twice a day in addition to the fluconazole treatment for 2 weeks. New dentures were made for the third group. Palatal swabs and smears were taken from each subject before, immediately after, and 2 weeks after treatment and these samples were examined myocologically. It was found that for generalized simple denture stomatitis, treatment with fluconazole in conjunction with chlorhexidine resulted in greater improvement of palatal inflammation and a decrease in candidal colonization than that with fluconazole alone or making new dentures without medication.

Candida and oral candidosis: a review

Candida species are the most common fungal pathogens isolated from the oral cavity. Their oral existence both as a commensal and an opportunist pathogen has intrigued clinicians and scientists for many decades, and recent investigations have revealed many attributes of this fungus contributing to its pathogenicity. In addition, the advent of the human immunodeficiency virus infection and AIDS has resulted in a resurgence of oral Candida infections. Clinicians are witnessing not only classic forms of the diseases but also newer clinical variants such as erythematous candidosis, rarely described hithertofore. Therefore, this review is an attempt at detailing the current knowledge on Candida and oral candidoses together with the newer therapeutic regimes employed in treating these mycoses.

Esophageal infections: risk factors, presentation, diagnosis, and treatment

Infections of the esophagus are unusual in the general population and strongly imply immunodeficiency, although immunocompetent individuals are not exempt. HIV infection is predominant among risk factors for infectious esophagitis. For all immunocompromised patients, the most frequently identified esophageal pathogens are Candida, CMV, and HSV. Peculiar to HIV-infected patients are idiopathic esophageal ulcers as well as unusual bacteria and parasites. Patterns of presentation differ with each infecting organism, and clinical features should be used as a guide in achieving a correct diagnosis. For example, a patient with AIDS presenting with esophageal symptoms and thrush, along with abdominal pain, nausea, vomiting, and fever, is unlikely to resolve all symptoms with empiric antifungal therapy alone. Parsimony of diagnosis does not hold among immunodeficient patients in whom concurrent infections are common. Accurate and timely diagnoses are essential as effective treatments are available for particular etiologies. Finally, among immunocompromised patients, all esophageal symptoms are not necessarily due to an infection, and possible diagnoses of pill esophagitis, acid-peptic injury, or structural and functional abnormalities should not be overlooked.