Drug Susceptibility Profiling of Prototheca Species Isolated from Cases of Human Protothecosis.

Prototheca are unicellular, achlorophyllous, yeast-like microalgae that occur in a wide range of natural habitats. At least five species have been implicated as the causative agents of opportunistic infections of men. Human protothecosis typically manifests as cutaneous, articular, or systemic disease. Treatment is largely empirical with poorly predictable and often unsuccessful outcomes. This is largely due to the frequently observed resistance of Prototheca species to conventional antimicrobial agents. This work is the first to perform drug susceptibility profiling exclusively on isolates from human cases of protothecosis. A total of 23 such isolates were tested against amphotericin B and 9 azoles, including efinaconazole and luliconazole, whose activities against Prototheca have never been studied before. Efinaconazole was the most active, with median minimum inhibitory concentration (MIC) and minimum algicidal concentration (MAC) values of 0.031 mg/L and 0.063 mg/L, respectively. Fluconazole and luliconazole had the lowest activity, with median MIC and MAC values of 128 mg/L. To conclude, amphotericin B and most of the azoles showed in vitro activity, with an algicidal rather than algistatic effect, against Prototheca. Still, the activity of individual drugs differed significantly between the species and even between strains of the same species. These differences can be attributed to a species-specific potential for acquiring drug resistance, which, in turn, might be linked to the treatment history of the patient from whom the strain was recovered. The results of this study underscore the potential clinical utility of efinaconazole as a promising therapeutic agent for the treatment of human protothecosis.

In vitro antifungal susceptibility profile of Iranian Fusarium isolates: Emphasising on the potent inhibitory effect of efinaconazole compared to other drugs.

BACKGROUND: Fusarium species are opportunistic human pathogens that remarkably cause fungal infections ranging from superficial to fatal invasive disseminated infections. Fusarium species are notoriously resistant to the majority of antifungal agents. OBJECTIVES: Therefore, detailed studies regarding in vitro susceptibility are required and may lead to a better prognosis of severe infections. METHODS: We evaluated 25 antifungal drugs in vitro against 282 clinical and environmental Fusarium isolates. RESULTS: Fusarium species demonstrated high MICs/MECs values to the most commonly used antifungal drugs in clinical practice. The geometric mean (GM) MICs for luliconazole (0.004 µg/ml) and lanoconazole (0.012 µg/ml) were the lowest, followed by efinaconazole (0.98 µg/ml) and amphotericin B (1.04 µg/ml). CONCLUSIONS: Efinaconazole, a novel triazole, may be a promising candidate for the treatment of superficial Fusarium infections. Furthermore, the development of systemic formulations of these drugs as well as further in vitro and in vivo investigations could aid in the treatment of systemic fusariosis.

In vitro activities of 8 antifungal agents against geophilic dermatophyte isolates.

BACKGROUND: Members of the Nannizzia gypsea complex are globally the most common geophilic dermatophytes which cause infection in animals and human. Although the susceptibility patterns of anthropophilic or zoophilic dermatophyte species to antifungal agents are well documented, the effectiveness of such drugs against geophilic species have rarely been explored. OBJECTIVES: This study was aimed to evaluate the in vitro antifungal activity of common and new antifungals against a set of environmental and clinical geophilic dermatophyte isolates. METHODS: 108 soil and clinical geophilic isolates from two genera Nannizzia (N. fulva n = 59; N. gypsea n = 43) and Arthroderma (A. quadrifidum n = 4; A. gertleri n = 1; A. tuberculatum n = 1) were included in the study. The in vitro antifungal susceptibility patterns of eight common and new antifungals against the isolates were determined according to broth microdilution method and by CLSI M38-A3 (3rd edition) protocol. RESULTS: MIC values across all isolates from five species ranged as: luliconazole: 0.0002-0.002 µg/ml, terbinafine: 0.008-0.125 µg/ml, efinaconazole: 0.008-0.125 µg/ml, ciclopirox olamine: 0.03-0.5 µg/ml, itraconazole: 0.125-1 µg/ml, amorolfine hydrochloride: 0.125-4 µg/ml, griseofulvin: 0.25-2 µg/ml and tavaborole: 1-8 µg/ml, respectively. CONCLUSION: Luliconazole, terbinafine and efinaconazole exhibited the highest in vitro efficacy, regardless of the dermatophyte species. Further surveillance studies are recommended to confirm the implication of such in vitro data for the clinical recovery rate of dermatophytosis with geophilic species following antifungal therapy.

Development and Validation of HPLC Method for Efinaconazole: Application to Human Nail Permeation Studies.

Efinaconazole is the first azole derivative approved by FDA for the topical treatment of onychomycosis. The objective of present study was to develop and validate HPLC method for estimation of efinaconazole in ex vivo human nail permeation study samples. The chromatographic analysis was performed on a HPLC system equipped with diode array detector. The efinaconazole and internal standard (IS) were extracted from the human nail samples by using the protein precipitation method. The samples were injected on to 5 µm Polar C18 100Å, 4.6 mm × 150 mm column. The mobile phase consisted of 0.01 M potassium dihydrogen phosphate: acetonitrile (36:64) and eluent was monitored at 205 nm. The chromatographic separation of drug and analyte was achieved using isocratic elution at flow rate of 1 mL/min with a total run time of 15 min. The efinaconazole and IS were eluted at 6.4 ± 0.5 and 8.3 ± 0.5 min, respectively. The developed method was validated as per FDA guidelines, and the results met with acceptance criteria. The method developed was specific, and the analyte concentrations were linear at range of 50 to 10000 ng/mL (R2 ≥ 0.9981). The validated HPLC method was applied for quantifying efinaconazole in human nail permeation study samples. The permeation of efinaconazole was increased by twofolds with Labarfac CC (15135.4 ± 2233.9 ng/cm2) compared to formulations containing Transcutol P (6892.0 ± 557.6 ng/cm2) and Labrasol (7266.1 ± 790.6 ng/cm2). The study results demonstrate that developed efinaconazole HPLC method can be employed for formulation evaluation and clinical studies.

[ANALYSIS OF PATCH TEST RESULTS FOR INDIVIDUAL INGREDIENTS IN PATIENTS WITH ALLERGIC CONTACT DERMATITIS CAUSED BY 10% EFINACONAZOLE NAIL SOLUTION].

BACKGROUND: Ten percent efinaconazole nail solution (EFCZ solution) is a new topical triazole antifungal drug, and we sometimes encounter patients with allergic contact dermatitis (ACD) caused by EFCZ solution in our outpatient clinic. However, no previous reports have summarized the patch test (PT) results obtained for individual ingredients in several patients with EFCZ solution-induced ACD. OBJECTIVES: This study aimed to 1) confirm the causative agent of EFCZ solution-induced ACD based on PT of individual ingredients and 2) analyze the optimal concentration and vehicle for such PT on the basis of previous studies. PATIENTS AND METHODS: We clinically diagnosed eight patients with EFCZ solution-induced ACD from Sep. 2014 to Aug. 2021, and performed 48-hour closed PT using EFCZ solution and its ingredients. Readings were done on days (D) 2, 3, and 7 according to the International Contact Dermatitis Research Group criteria. RESULTS: Six of the 8 patients underwent PT with EFCZ solution, and all showed + to +++ reactions on D3. The results for the main component, EFCZ, were + to +++ on D3 in all patients. Two patients were patch tested with both 10% EFCZ in ethanol and 10% EFCZ in petrolatum, which produced similar reactions. One patient had an allergic reaction to ethanol. CONCLUSIONS: The causative agent of EFCZ solution-induced ACD was EFCZ in all patients. For PT, we recommend EFCZ solution as is, its 10-fold dilution and 1% and 0.1% EFCZ in petrolatum.

A comparative study between two antifungal agents, Luliconazole and Efinaconazole, of their preventive effects in a Trichophyton-infected guinea pig onychomycosis model.

An efficacious period of two topical antifungal drugs was compared in a Trichophyton mentagrophytes-infected onychomycosis model in guinea pigs treated with antifungal drugs prior to infection. Luliconazole 5% (LLCZ) and efinaconazole 10% (EFCZ) test solutions were applied to the animals' nails once daily for 2 weeks followed by a nontreatment period of 2, 4, and 8 weeks. After each nontreatment period, the nails were artificially infected by the fungus. Drug efficacy was quantitatively evaluated by qPCR and histopathological examination of the nails collected following a 4-week post-infection period. The fungal infection was confirmed in the untreated group. Both LLCZ and EFCZ prevented fungal infection in the treated groups with the nontreatment period of 2 weeks. After the nontreatment period of 4 weeks, no infection was observed in the LLCZ-treated group; however, infection into the nail surface and fungal invasion into the nail bed were observed in the EFCZ-treated group. After the nontreatment period of 8 weeks, fungi were found in the nail surface and nail bed in some nails treated with EFCZ; however, no infection was observed in the nail bed of the LLCZ-treated group. The results suggest that LLCZ possesses longer-lasting antifungal effect in nails of the guinea pigs than EFCZ, and that this animal model could be useful for translational research between preclinical and clinical studies to evaluate the pharmacological efficacy of antifungal drugs to treat onychomycosis. This experimentally shown longer-lasting preventive effects of LLCZ could also decrease the likelihoods of onychomycosis recurrence clinically.

Effect of onychomycosis and treatment on patient-reported quality-of-life outcomes: A systematic review.

BACKGROUND: Onychomycosis is the most common nail disorder, often causing physical, emotional, and aesthetic consequences. The effect of both the condition itself and treatment on quality of life has not been well studied. OBJECTIVE: The objectives of this study were to systematically review the available literature describing the effect of onychomycosis and treatment on quality of life. METHODS: We performed a search of the onychomycosis literature published before April 13, 2020. Articles were included in the review if primary data were presented, patient-reported outcome measures were used, and onychomycosis was specifically examined. RESULTS: Thirty studies were included in the final analysis. Poorest quality-of-life scores were associated with women and fingernail involvement. Quality-of-life scores improved from baseline with all treatment types; there were greater improvements reported with oral treatments compared with topical ones. CONCLUSIONS: This review affirms that onychomycosis significantly influences quality of life, warranting effective treatment. All treatments resulted in quality-of-life improvements; however, studies on oral and topical therapies were of higher quality than those evaluating devices. Increased efforts are needed to understand the effect of the disease and therapy as assessed by validated, nail-specific outcome measures that accurately assess patients' cosmetic, physical, and social difficulties.

Molecular identification and antifungal susceptibility profiles of Candida dubliniensis and Candida africana isolated from vulvovaginal candidiasis: A single-centre experience in Iran.

BACKGROUND: Vulvovaginal candidiasis (VVC) is a common and debilitating long-term illness affecting million women worldwide. This disease is caused mainly by Candida albicans and a lesser extent by other species, including the two phylogenetically closely related pathogens Candida africana and Candida dubliniensis. OBJECTIVES: In this study, we report detailed molecular epidemiological data about the occurrence of these two pathogenic yeasts in Iranian patients affected by VVC, or its chronic recurrent form (RVVC), and provide, for the first time, data on the antifungal activity of two new drugs, efinaconazole (EFN) and luliconazole (LUL). METHODS: A total of 133 vaginal yeast isolates, presumptively identified as C albicans by phenotypic and restriction analysis of rDNA, were further analysed by using a specific molecular method targeting the HWP1 gene. All C africana and C dubliniensis isolates were also tested for their in vitro susceptibility to a panel of modern and classical antifungal drugs. RESULTS AND CONCLUSIONS: Based on the molecular results, among 133 germ-tube positive isolates, we identify 119 C albicans (89.47%), 11 C africana (8.27%) and 3 C dubliniensis (2.26%) isolates. C africana and C dubliniensis showed low MIC values for most of the antifungal drugs tested, especially for EFN and LUL, which exhibited a remarkable antifungal activity. High MIC values were observed only for nystatin and terbinafine. Although C albicans remains the most common Candida species recovered from Iranian VVC/RVVC patients, our data show that its prevalence may be slightly overestimated due to the presence of difficult-to-identify closely related yeast, especially C africana.

Long-term Efficacy and Safety of Once-daily Efinaconazole 10% Topical Solution (Jublia) for Dermatophyte Toenail Onychomycosis: An Interim Analysis.

Onychomycosis, a difficult-to-treat fungal nail infection, is more prevalent in the elderly. Efinaconazole 10% topical solution is a firstline therapy for onychomycosis, based on phase III trials of 12-month treatment; the slow growth of onychomycotic nails suggests a longer treatment period may increase efficacy. This is the first efficacy and safety data for a 24-month duration of efinaconazole 10% topical solution treatment for onychomycosis. Enrolled patients (N = 101) with mild to moderate distal lateral subungual onychomycosis applied efinaconazole to all affected toenails once daily for 18-24 months. Efficacy and safety were evaluated at months 6, 12, 18, and 24 (M6, M12, M18, and M24). The study is ongoing; to date, 47 patients have completed to M24. Mycological cure (MC) was 60.0% at M12, increasing to 74.2% at M24; effective cure (MC and ≤10% clinical involvement of the target toenail) was 17.8% at M12, rising to 19.4% at M24. Mild to moderate application site reactions were the only efinaconazole-related adverse events in 8 patients (7.9%). Increased age, increased severity of onychomycosis, and the presence of mixed infections (dermatophyte plus non-dermatophyte moulds) may drive a need for longer treatment durations. Although the data are interim, there is a trend of increasing efficacy beyond M12 use, without increased safety risk, even in patients >70 years of age.

Effect of Penetration Enhancers on Toenail Delivery of Efinaconazole from Hydroalcoholic Preparations.

The incorporation of permeation enhancers in topical preparations has been recognized as a simple and valuable approach to improve the penetration of antifungal agents into toenails. In this study, to improve the toenail delivery of efinaconazole (EFN), a triazole derivative for onychomycosis treatment, topical solutions containing different penetration enhancers were designed, and the permeation profiles were evaluated using bovine hoof models. In an in vitro permeation study in a Franz diffusion cell, hydroalcoholic solutions (HSs) containing lipophilic enhancers, particularly prepared with propylene glycol dicaprylocaprate (Labrafac PG), had 41% higher penetration than the HS base. Moreover, the combination of hydroxypropyl-ß-cyclodextrin with Labrafac PG further facilitated the penetration of EFN across the hoof membrane. In addition, this novel topical solution prepared with both lipophilic and hydrophilic enhancers was physicochemically stable, with no drug degradation under ambient conditions (25 °C, for 10 months). Therefore, this HS system can be a promising tool for enhancing the toenail permeability and therapeutic efficacy of EFN.

Labeled use of efinaconazole topical solution 10% in treating onychomycosis in children and a review of the management of pediatric onychomycosis.

Onychomycosis is a difficult to treat condition whose prevalence is increasing. Until recently, there was no FDA approved antifungal agent for the treatment of onychomycosis in children. Although systemic antifungal agents are effective, their use is restricted by the potential adverse events and drug-drug interactions. There is evidence regarding the safety and efficacy of topical antifungal agents for pediatric onychomycosis. We have summarized the results of a recently published study using efinaconazole topical solution 10% to treat onychomycosis in children and discuss management of pediatric onychomycosis. In a multicenter, open-label phase 4 study, efinaconazole 10% solution was applied topically once daily in children aged 6 to 16 years with mild to severe, culture positive, distal and lateral subungual onychomycosis. Treatment was for 48 weeks with a follow-up at week 52. Pharmacokinetics was performed in a subset of patients. There were 62 patients enrolled in the study. At week 52, the efficacy was mycological cure rate 65% and complete cure rate 40%. All treatment-emergent adverse events (TEAE) were mild to moderate in severity with none resulting in study discontinuation. The only treatment-related TEAE was ingrown toenail. Efinaconazole was detected at low levels in plasma. Efinaconazole topical solution 10% is effective and safe in treating onychomycosis in children age 6 to 16 years and was recently FDA-approved for this indication. The on-label use of other topical agents, tavaborole solution 5% and ciclopirox nail lacquer solution 8% is reviewed. We also briefly discuss the use of oral agents, terbinafine, itraconazole, and fluconazole in pediatric onychomycosis.

Efinaconazole topical solution 10%: Formulation and efficacy assessment in the treatment of toenail onychomycosis.

BACKGROUND: Efinaconazole is non-lacquer-based with a low surface tension that efficiently targets delivery of active ingredient into the nail and nail bed. OBJECTIVES: To develop an optimal, stable formulation of efinaconazole topical solution 10% (ETS10). METHODS: We evaluated the safety and efficacy of ETS10 on 10 Iranian participants in a pilot, single-group and before-after clinical study, for up to 8 weeks in onychomycosis. RESULTS: The study showed reasonable results concerning the short period of treatment. During the period of storage, the formulation showed no variation in colour, odour and pH. The average pH at initial, 1st, 6th and 12th months was 4.65, 4.64, 4.65 and 4.64, respectively. The assay of an active pharmaceutical ingredient in the formulation was desired over the whole period. This indicates that antimicrobial activity has been adequate and efficient. A significant decrease in Investigator Global Assessment (IGA) of the target toenails was also defined as the efficacy endpoint. The median score for IGA at baseline visit was 3 out of 5 which decreased to 2 out of 5 and the decrease was statistically significant. CONCLUSION: The study clarifies the new efficacy of ETS10 in subjects with onychomycosis and passed the safety study successfully. These properties may develop the potentiality of ETS10 as a good treatment option for patients with onychomycosis.

Antifungal Activity of a Novel Triazole, Efinaconazole and Nine Comparators against 354 Molecularly Identified Aspergillus Isolates.

Management of superficial aspergillosis is a major challenge owing to the frequent relapses and treatment failure, which may pose a potential risk, thereby gradually developing resistant species. Therefore, necessitating the development of new antifungals with higher potency should be considered as alternative strategies for efficient management of infections. We aimed to investigate the susceptibility of Aspergillus isolates toward a novel triazole, efinaconazole, in comparison with various classes of antifungal drugs. Antifungal susceptibility testing was performed according to the Clinical and Laboratory Standards Institute M38-A2 guidelines. Efinaconazole exhibited poor activity against mutant A. fumigatus strains, A. niger sensu stricto, and A. tubingensis with GM MIC values of 3.62, 1.62, and 2 µg/ml, respectively; however, surprisingly, it efficiently inhibited the growth of A. terreus sensu stricto, followed by wild-type A. fumigatus and A. flavus with GM MIC values of 0.29, 0.42, and 0.52 µg/ml, respectively. Presumably, efinaconazole is inefficient in aspergillosis treatment due to the low susceptibility of A. niger sensu stricto, A. tubingensis, and mutant A. fumigatus; however, it may be effective in treating superficial aspergillosis caused by wild-type A. fumigatus, A. terreus sensu stricto, and A. flavus. Further studies are needed to determine how these findings may translate into in vivo efficacy.

Ciclopirox and Efinaconazole Transungual Permeation, Antifungal Activity, and Proficiency To Induce Resistance in Trichophyton rubrum.

Onychomycosis is a nail fungal infection, mostly caused by dermatophytes. The treatment efficacy is impaired by difficulties of reaching effective drug levels at the site of infection; frequent relapses occur after cessation of antifungal therapy. The aim of the study was to compare two commercial products containing ciclopirox or efinaconazole for antimycotic activity and antifungal drug resistance. A study of permeation and penetration through bovine hoof membranes, as a nail model, was performed to evaluate the antimycotic activity of permeates against clinical isolates of selected fungi, and the frequency of spontaneous in vitroTrichophyton rubrum-resistant strains was assessed by broth microdilution assays. The results suggest that ciclopirox creates a depot in the nail, leading to a gradual release of the drug over time with action on both the nail plate and bed. Conversely, efinaconazole, mildly interacting with nail keratin, mainly exerts its antifungal activity in the nail bed. However, in the case of T. rubrum, the antifungal activities of the drugs in the nail plate seem comparable. Finally, efinaconazole showed a potential for induction of resistance in T. rubrum, which may limit its efficacy over time. Ciclopirox did not show any potential to induce resistance in T. rubrum and appears endowed with a more complete activity than efinaconazole in the management of onychomycosis as the nail keratin is a substrate for the growth of fungal cells, and the availability of drug in large concentration just in the nail bed may not be sufficient to guarantee the complete eradication of pathogens.

Onychomycosis: Treatment and prevention of recurrence.

Onychomycosis is a fungal nail infection caused by dermatophytes, nondermatophytes, and yeast, and is the most common nail disorder seen in clinical practice. It is an important problem because it may cause local pain, paresthesias, difficulties performing activities of daily living, and impair social interactions. The epidemiology, risk factors, and clinical presentation and diagnosis of onychomycosis were discussed in the first article in this continuing medical education series. In this article, we review the prognosis and response to onychomycosis treatment, medications for onychomycosis that have been approved by the US Food and Drug Administration, and off-label therapies and devices. Methods to prevent onychomycosis recurrences and emerging therapies are also described.

Efficacy of combination therapy with efinaconazole 10% solution and 1064 nm Nd:YAG laser for treatment of toenail onychomycosis.

BACKGROUND: Onychomycosis is a common but difficult to treat nail disorder. Treatment strategies thus far have included oral and topical antifungals, surgical treatment and recently lasers have emerged as a therapeutic modality. OBJECTIVE: The objective of this study was to assess whether efinaconazole together with laser would result in greater clinical and mycologic cure and lower rate of relapse compared to efinaconazole alone. METHODS: Thirty subjects were randomized to either self-apply efinaconazole 10% once daily for 48 weeks, or follow the same treatment plan but also receive six treatments with a 1064 nm Nd: YAG laser every 4 weeks. The primary endpoint was to assess the proportion of subjects who achieved complete cure at week 52. RESULTS: The combination therapy group showed significantly quicker mycological cure at the 48- and 52-week follow-up. CONCLUSION: Both efinaconazole and combination with laser were efficacious treatment, but the combination therapy leads to quicker resolution with fewer rate of relapse.

In Vitro Antifungal Activity of Novel Triazole Efinaconazole and Five Comparators against Dermatophyte Isolates.

The objective of this study was to assess the in vitro activity of the novel triazole antifungal drug, efinaconazole, and five comparators (luliconazole, lanoconazole, terbinafine, itraconazole, and fluconazole) against a large collection of Trichophyton interdigitale and Trichophyton rubrum clinical isolates. The geometric mean MICs were the lowest for luliconazole (0.0005 µg/ml), followed by lanoconazole (0.002 µg/ml), efinaconazole (0.007 µg/ml), terbinafine (0.011 µg/ml), itraconazole (0.095 µg/ml), and fluconazole (12.77 µg/ml). It appears that efinaconazole, lanoconazole, and luliconazole are promising candidates for the treatment of dermatophytosis due to T. interdigitale and T. rubrum.

In Vitro Activities of Luliconazole, Lanoconazole, and Efinaconazole Compared with Those of Five Antifungal Drugs against Melanized Fungi and Relatives.

The in vitro activities of novel azoles compared to those of five antifungal drugs against clinical (n = 28) and environmental (n = 102) isolates of black mold and melanized yeast were determined. Luliconazole and lanoconazole had the lowest geometric mean MICs, followed by efinaconazole, against tested isolates compared to the other drugs. Therefore, it appears that these new imidazole and triazole drugs are promising candidates for the treatment of infections due to melanized fungi and their relatives.