Terbinafine in the treatment of dermatophyte toenail onychomycosis: a meta-analysis of efficacy for continuous and intermittent regimens

Dermatophytes: Update on Clinical Epidemiology and Treatment

Dermatophytes represent the largest and most common group of fungal infections, impacting 25% of the global population. Among them, Trichophyton rubrum has emerged as the predominant species, responsible for a range of conditions such as tinea corporis, tinea pedis, onychomycosis, tinea cruris, and tinea manuum. Although dermatophyte incidence varies geographically, there is a noticeable rise in cases caused by T. indotineae, a strain that exhibits resistance to terbinafine. In the past decade zoophilic dermatophyte T. mentagophytes genotype VII (now known as T. interdigitale) gains a growing importance, due to its increasing frequency, the severity of the clinical manifestation and mode of transmission. Tinea infections present with various clinical symptoms and can affect individuals of all ages, from tinea pedis in adults to tinea capitis in children. Among adults globally, tinea unguium (onychomycosis) is the most common form of dermatophytosis, affecting 5.5% of the general population. Tinea unguium is more frequently seen in developed countries, while tinea capitis is more common in developing nations. The COVID-19 pandemic has led to an increase in cases of tinea faciei, likely due to prolonged mask-wearing. Terbinafine remains the preferred treatment for dermatophyte infections worldwide due to its potent fungicidal properties, minimal risk of drug interactions, and fewer side effects compared to other oral antifungals. Itraconazole and terbinafine appear to be equally effective and safe for treating tinea cruris and tinea corporis. However, the rising resistance of dermatophytes to these antifungal drugs, along with frequent recurrences of dermatophytosis in certain regions, is becoming a significant public health concern.

Onychomycosis

Onychomycosis is a fungal infection of the nail, and the most common nail infection worldwide, causing discoloration and thickening of the nail plate. It is predominantly caused by dermatophytes. Clinical presentation is polymorphous. Diagnosis must be confirmed by mycological examination before initiating any therapy. Management is an ongoing challenge, often requiring several months' treatment, with a high risk of recurrence. Treatment must be adapted to clinical presentation and severity and to the patient's history and wishes. Debridement of all infected keratin is the first step, reducing fungal load. Systemic treatments are more effective than topical treatments, and combining the two increases the cure rate. Terbinafine is the drug of choice for dermatophyte onychomycosis, due to low drug interaction and good cost-effectiveness. Itraconazole and fluconazole are broad-spectrum antifungals that are effective against dermatophytes, yeasts, and some non-dermatophytic molds. Recurrence rates for onychomycosis are high. Prophylactic application of topicals and avoiding walking barefoot in public places may help prevent recurence.

Reliable and rapid identification of terbinafine resistance in dermatophytic nail and skin infections

BACKGROUND

Fungal infections are the most frequent dermatoses. The gold standard treatment for dermatophytosis is the squalene epoxidase (SQLE) inhibitor terbinafine. Pathogenic dermatophytes resistant to terbinafine are an emerging global threat. Here, we determine the proportion of resistant fungal skin infections, analyse the molecular mechanisms of terbinafine resistance, and validate a method for its reliable rapid identification.

METHODS

Between 2013 and 2021, we screened 5634 consecutively isolated Trichophyton for antifungal resistance determined by hyphal growth on Sabouraud dextrose agar medium containing 0.2 μg/mL terbinafine. All Trichophyton isolates with preserved growth capacity in the presence of terbinafine underwent SQLE sequencing. Minimum inhibitory concentrations (MICs) were determined by the broth microdilution method.

RESULTS

Over an 8-year period, the proportion of fungal skin infections resistant to terbinafine increased from 0.63% in 2013 to 1.3% in 2021. Our routine phenotypic in vitro screening analysis identified 0.83% (n = 47/5634) of Trichophyton strains with in vitro terbinafine resistance. Molecular screening detected a mutation in the SQLE in all cases. Mutations L393F, L393S, F397L, F397I, F397V, Q408K, F415I, F415S, F415V, H440Y, or A398 A399 G400 deletion were detected in Trichophyton rubrum. Mutations L393F and F397L were the most frequent. In contrast, all mutations detected in T. mentagrophytes/T. interdigitale complex strains were F397L, except for one strain with L393S. All 47 strains featured significantly higher MICs than terbinafine-sensitive controls. The mutation-related range of MICs varied between 0.004 and 16.0 μg/mL, with MIC as low as 0.015 μg/mL conferring clinical resistance to standard terbinafine dosing.

CONCLUSIONS

Based on our data, we propose MIC of 0.015 μg/mL as a minimum breakpoint for predicting clinically relevant terbinafine treatment failure to standard oral dosing for dermatophyte infections. We further propose growth on Sabouraud dextrose agar medium containing 0.2 μg/mL terbinafine and SQLE sequencing as fungal sporulation-independent methods for rapid and reliable detection of terbinafine resistance.

Onychomycosis: Old and New

Onychomycosis is a common chronic fungal infection of the nail that causes discoloration and/or thickening of the nail plate. Oral agents are generally preferred, except in the case of mild toenail infection limited to the distal nail plate. Terbinafine and itraconazole are the only approved oral therapies, and fluconazole is commonly utilized off-label. Cure rates with these therapies are limited, and resistance to terbinafine is starting to develop worldwide. In this review, we aim to review current oral treatment options for onychomycosis, as well as novel oral drugs that may have promising results in the treatment of onychomycosis.

Nail Society of India (NSI) Recommendations for Pharmacologic Therapy of Onychomycosis

Onychomycosis (OM) is the commonest cause of dystrophic nails, responsible for upto 50% of cases. Apart from significantly damaging the nails, quality of life, and self-image of the sufferer, it also acts as a reservoir of fungal infections carrying important implications for emerging recalcitrant dermatophytoses. Treatment of OM is based on guidelines released almost a decade back, in addition to published literature and personal preferences. Hence, an expert group of nail society of India (NSI) worked towards drafting these guidelines aimed at compiling recommendations for pharmacologic treatment of OM, based on scientific evidence, along with practical experience. The group did an extensive analysis of available English language literature on OM published during the period 2014-2022. The evidence compiled was graded and discussed to derive consensus recommendations for practice. Special focus was placed on combination therapies and adjunct therapies, including experience of members, to improve treatment outcomes.

Allylamines, Benzylamines, and Fungal Cell Permeability: A Review of Mechanistic Effects and Usefulness against Fungal Pathogens

Allylamines, naftifine and terbinafine, and the benzylamine, butenafine, are antifungal agents with activity on the fungal cell membrane. These synthetic compounds specifically inhibit squalene epoxidase, a key enzyme in fungal sterol biosynthesis. This results in a deficiency in ergosterol, a major fungal membrane sterol that regulates membrane fluidity, biogenesis, and functions, and whose damage results in increased membrane permeability and leakage of cellular components, ultimately leading to fungal cell death. With the fungal cell membrane being predominantly made up of lipids including sterols, these lipids have a vital role in the pathogenesis of fungal infections and the identification of improved therapies. This review will focus on the fungal cell membrane structure, activity of allylamines and benzylamines, and the mechanistic damage they cause to the membrane. Furthermore, pharmaceutical preparations and clinical uses of these drugs, mainly in dermatophyte infections, will be reviewed.

Updated Perspectives on the Diagnosis and Management of Onychomycosis

Onychomycosis is the most common nail disease encountered in clinical practice and can cause pain, difficulty with ambulation, and psycho-social problems. A thorough history and physical examination, including dermoscopy, should be performed for each patient presenting with nail findings suggestive of onychomycosis. Several approaches are available for definitive diagnostic testing, including potassium hydroxide and microscopy, fungal culture, histopathology, polymerase chain reaction, or a combination of techniques. Confirmatory testing should be performed for each patient prior to initiating any antifungal therapies. There are several different therapeutic options available, including oral and topical medications as well as device-based treatments. Oral antifungals are generally recommended for moderate to severe onychomycosis and have higher cure rates, while topical antifungals are recommended for mild to moderate disease and have more favorable safety profiles. Oral terbinafine, itraconazole, and griseofulvin and topical ciclopirox 8% nail lacquer, efinaconazole 10% solution, and tavaborole 5% solution are approved by the Food and Drug Administration for treatment of onychomycosis in the United States and amorolfine 5% nail lacquer is approved in Europe. Laser treatment is approved in the United States for temporary increases in clear nail, but clinical results are suboptimal. Oral fluconazole is not approved in the United States for onychomycosis treatment, but is frequently used off-label with good efficacy. Several novel oral, topical, and over-the-counter therapies are currently under investigation. Physicians should consider the disease severity, infecting pathogen, medication safety, efficacy and cost, and patient age, comorbidities, medication history, and likelihood of compliance when determining management plans. Onychomycosis is a chronic disease with high recurrence rates and patients should be counseled on an appropriate plan to minimize recurrence risk following effective antifungal therapy.

Pathogenesis, Immunology and Management of Dermatophytosis

Dermatophytic infections of the skin and appendages are a common occurrence. The pathogenesis involves complex interplay of agent (dermatophytes), host (inherent host defense and host immune response) and the environment. Infection management has become an important public health issue, due to increased incidence of recurrent, recalcitrant or extensive infections. Recent years have seen a significant rise in incidence of chronic infections which have been difficult to treat. In this review, we review the literature on management of dermatophytoses and bridge the gap in therapeutic recommendations.

Tinea pedis-An embarrassing problem for health and beauty-A narrative review

Fungal infections present with a broad spectrum of diseases in humans (from relatively mild superficial infections of the skin and mucous membranes to the invasive or chronic infections of internal organs, which have a high mortality rate). Globally, up to 1.6 million people die each year as a result of various types of mycoses. Currently, many scientific studies focus on the best possible understanding of the aspects of the epidemiology and pathogenesis of invasive mycoses and effective methods to combat them. However, mycoses of the skin and its appendages remain a relatively less explored area. In some communities, superficial mycoses are a frequent problem as they affect nearly 70% of the population, an example of which is the athlete's foot. It involves the nails (onychomycosis) and skin (tinea pedis). It is mainly caused by keratin-decomposing dermatophyte fungi. Less often, infections are caused by non-dermatophyte moulds (Fusarium, Aspergillus, Scopulariopsis) or yeasts. Several factors have been listed as having substantial influence on the development of dermatophytosis, including those related to climate, season, geographical region, as well as to demography, socioeconomic and cultural customs, professions or contact with animals. In this review, we summarise the current knowledge about aetiology, epidemiology, diagnostics and therapy of tinea pedis with a special focus to the role of podologic management in spreading, prevention and therapy of mycoses. The article presents up-to-date knowledge on the management of the patient from the diagnosis, treatment and skincare, to counselling on how to prevent fungal skin infections in the long term.

Severe onychomycosis management with oral terbinafine in a kidney transplantation setting: Clinical follow-up by image analysis

BACKGROUND

Severe onychomycosis treatment in kidney transplant recipients (KTR) is challenging because of drug interactions and adverse events. Tacrolimus remains the antirejection treatment (ART) of choice in kidney transplantation but tolerance with systemic terbinafine for the management of severe onychomycosis has not been studied.

OBJECTIVE

This study illustrates severe onychomycosis management in a kidney transplantation setting and investigates systemic terbinafine tolerance profile in KTR.

PATIENTS/METHODS

We retrospective analysed clinical data of KTR with a confirmed diagnosis of severe onychomycosis.

RESULTS

We retrieved a total of 29 KTR with severe onychomycosis needing an oral treatment to manage onychomycosis. In 55.1% (16/29) KTR, altered renal biological parameters or lack of guidelines to manage severe onychomycosis were the main reasons to deterring clinicians from prescribing oral treatments. 13 patients received an oral terbinafine treatment (9, 3 and 1 with a tacrolimus, cyclosporine and everolimus-based ART, respectively). Clinical and biological follow-up did not reveal severe drug interactions. ART blood levels showed significant variations in 2 patients without clinical consequences in renal graft. Two patients reported mild adverse events but after only one dose of terbinafine. Using an open-source image analysis program, clinical evolution of onychomycosis could be retrospectively quantified and followed up.

CONCLUSIONS

The results presented here suggest that oral terbinafine can be proposed to treat severe onychomycosis with an acceptable tolerance profile in KTR with different ART such as tacrolimus and highlight the need of multicentric studies to establish guidelines for onychomycosis treatment in KTR.

Safety of current therapies for onychomycosis

INTRODUCTION

Onychomycosis is the most common nail disease seen in clinical practice. Treatment options include systemic and topical therapies, as well as devices. Following clinical and mycologic diagnosis, treatment must be individualized, accounting for disease severity, infecting organism(s), comorbidities, patient characteristics and drug/device efficacy. Safety is the most important consideration in choosing the most appropriate therapeutic modality.

AREAS COVERED

This review covers currently available treatments for onychomycosis, with an emphasis on safety and tolerability. Medications and devices were analyzed for side effects, drug-drug interactions, and safety during pregnancy and breastfeeding.

EXPERT OPINION

Systemic antifungals offer greater efficacy for onychomycosis treatment but are limited by risks of systemic toxicity and drug-drug interactions. The risk of terbinafine-induced hepatotoxicity is negligible in healthy patients. Systemic therapies, especially azole antifungals, are associated with numerous drug-drug interactions, some of which are life-threatening and fatal. Thus, a detailed medication history is critical before prescribing these medications. Topical antifungals are well tolerated and generally safe, with only potential local side effects. Systemic and topical onychomycosis treatments should not be prescribed during pregnancy and breastfeeding. Laser therapy is likely less effective than systemic and topical therapies, but may be safely used during pregnancy and breastfeeding.

Treatment and management strategies of onychomycosis

Onychomycosis is one of the most prevalent and severe nail fungal infections, which is affecting a wide population across the globe. It leads to variations like nail thickening, disintegration and hardening. Oral and topical drug delivery systems are the most desirable in treating onychomycosis, but the efficacy of the results is low, resulting in a relapse rate of 25-30%. Due to systemic toxicity and various other disadvantages associated with oral therapy like gastrointestinal, hepatotoxicity, topical therapy is commonly used. Topical therapy improves patient compliance and reduces the cost of treatment. However, due to poor penetration of topical therapy across the nail plate, research is focused on different chemical, mechanical and physical methods to improve drug delivery. Penetration enhancers like Thioglycolic acid, Hydroxypropyl-β-cyclodextrin (HP-β-CD), Sodium lauryl sulfate (SLS), carbocysteine, N-acetylcysteine etc. have shown results enhancing the drug penetration across the nail plate. Results with physical techniques such as iontophoresis, laser and Photodynamic therapy are quite promising, but the long-term suitability of these devices is in need to be determined. In this article, a brief analysis of the treatment procedures, factors affecting drug permeation across nail plate, chemical, mechanical and physical devices used to increase the drug delivery through nails for the onychomycosis management has been achieved.

The efficacy and safety of pulse vs. continuous therapy for dermatophyte toenail onychomycosis

BACKGROUND

Onychomycosis is a chronic, fungal infection of the nails. Complete cure remains challenging, but oral antifungal medications have been successful in managing the fungus for a significant proportion of patients. Treatment with these drugs can be continuous or intermittent, albeit the evidence on their relative efficacies remains unclear.

OBJECTIVE

To determine the relative effectiveness and safety of pulse versus continuous administration, of three common oral therapies for dermatophyte onychomycosis, by conducting multiple-treatment meta-analysis.

METHODS

This systematic review and network meta-analysis compared the efficacy (as per mycological cure) and adverse event rates of three oral antifungal medications in the treatment of dermatophyte toenail onychomycosis, namely terbinafine, itraconazole and fluconazole. A total of 30 studies were included in the systematic review, while 22 were included in the network meta-analysis.

RESULTS

The likelihood of mycological cure was not significantly different between continuous and pulse regimens for each of terbinafine and itraconazole. Use of continuous terbinafine for 24 weeks - but not 12 weeks - was significantly more likely to result in mycological cure than continuous itraconazole for 12 weeks or weekly fluconazole for 9-12 months. Rank probabilities demonstrated that 24-week continuous treatment of terbinafine was the most effective. There were no significant differences in the likelihood of adverse events between any continuous and pulse regimens of terbinafine, itraconazole and fluconazole. Drug treatments were similar to placebo in terms of their likelihood of producing adverse events.

CONCLUSION

More knowledge about the fungal life cycle and drugs' pharmacokinetics in nail and plasma could further explain the relative efficacy and safety of the pulse and continuous treatment regimens. Our results indicate that in the treatment of dermatophyte toenail onychomycosis, the continuous and pulse regimens for terbinafine and itraconazole have similar efficacies and rates of adverse events.

Honokiol, magnolol and its monoacetyl derivative show strong anti-fungal effect on Fusarium isolates of clinical relevance

The antifungal activity of magnolol and honokiol, two naturally occurring hydroxylated biphenyls, and of their synthetic derivatives was evaluated on a collection of representative isolates of Fusarium oxysporum, F. solani and F. verticillioides of clinical and ecological concern. The tested compounds were proposed as a ‘natural’ alternative to conventional fungicides, even though a larger range of concentrations (5–400 μg/ml) was applied. The activity of magnolol and honokiol was compared with that of terbinafine (0.1–10 μg/ml), and fluconazole (1–50 μg/ml), two fungicides widely used in treating fungal infections on humans. Magnolol showed similar fungicidal activity compared to fluconazole, whereas honokiol was more effective in inhibiting mycelium growth compared to this fungicide on all tested clinical Fusarium spp. isolates. Compared to terbinafine, honokiol showed similar antifungal activity when tested on clinical F. solani isolates, whereas magnolol was less effective at all selected concentrations (5–400 μg/ml). The different position of the phenol-OH group, as well as its protection, explain different in vitro activities between magnolol, honokiol, and their derivatives. Furthermore, magnolol showed mycelium dry weight reduction at a concentration of 0.5 mM when tested on a set of agricultural isolates of Fusaria, leading to complete inhibition of some of them. Magnolol and honokiol are proposed as efficient and safe candidates for treating clinically relevant Fusaria.

A Practical Guide to Curing Onychomycosis: How to Maximize Cure at the Patient, Organism, Treatment, and Environmental Level

Onychomycosis is a fungal nail infection caused by dermatophytes, non-dermatophyte molds, and yeasts. Treatment of this infection can be difficult, with relapse likely to occur within 2.5 years of cure. The objective of this article is to review factors that can impact cure and to suggest practical techniques that physicians can use to maximize cure rates. Co-morbidities, as well as disease severity and duration, are among the many patient factors that could influence the efficacy of antifungal therapies. Furthermore, organism, treatment, and environmental factors that may hinder cure include point mutations, biofilms, affinity for non-target enzymes, and exposure to fungal reservoirs. To address patient-related factors, physicians are encouraged to conduct confirmatory testing and treat co-morbidities such as tinea pedis early and completely. To combat organism-focused factors, it is recommended that disruption of biofilms is considered, and drugs with multiple routes of delivery and unique mechanisms of action are prescribed when traditional agents are not effective. Extending follow-up periods, using combination treatments, and considering pulse regimens may also be of benefit. Through these practical techniques, physicians can maximize cure and limit the risk of relapse and re-infection.

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.

Blad-containing oligomer: a novel fungicide used in crop protection as an alternative treatment for tinea pedis and tinea versicolor

PURPOSE

The lack of novel antifungal drugs and the increasing incidence and severity of fungal infections are major concerns worldwide. Herein, we tested the activity of the Blad-containing oligomer (BCO), a new antifungal molecule already in use for agriculture, on Malassezia spp. and dermatophytes, the causal agents of human tinea versicolor and tinea pedis. Given the lack of a standard method for Malassezia susceptibility testing and the plethora of published methods, we also developed an improved method for this genus.

METHODOLOGY

The efficacy of BCO was assessed in vitro and compared to that of the drugs currently utilized in the treatment of tinea versicolor (fluconazole and itraconazole) and tinea pedis (itraconazole and terbinafine). For dermatophytes, the standard microdilution broth-based method was used, with small adjustments, and several broth formulations and inocula sizes were tested to develop an improved susceptibility method for Malassezia spp.

RESULTS

We successfully developed a microdilution broth-based method with considerable advantages over other available methods, and used it for all in vitro susceptibility tests of Malassezia spp. isolates. We report that, on a molar basis, BCO was more effective than fluconazole or itraconazole on most strains of Malassezia spp. isolated from clinical samples (n=29). By contrast, BCO was less effective than itraconazole or terbinafine on the common dermatophytes Trichophyton rubrum and Trichophyton interdigitale.

CONCLUSION

These data place BCO as a promising drug for the treatment of Malassezia-associated skin diseases. Further in vivo studies are now required to ascertain its applicability in the clinical setting.

The Diagnosis and Treatment of Nail Disorders

BACKGROUND

Nail disorders can arise at any age. About half of all nail disorders are of infectious origin, 15% are due to inflammatory or metabolic conditions, and 5% are due to malignancies and pigment disturbances. The differential diagnosis of nail disorders is often an area of uncertainty.

METHODS

This review is based on publications and guidelines retrieved by a selective search in PubMed, including Cochrane reviews, meta-analyses, and AWMF guidelines.

RESULTS

Nail disorders are a common reason for derma - tologic consultation. They are assessed by clinical inspection, dermatoscopy, diagnostic imaging, microbiological (including mycological) testing, and histopathological examination. Some 10% of the overall population suffers from onychomycosis, with a point prevalence of around 15%. Bacterial infections of the nails are rarer than fungal colonization. High-risk groups for nail disorders include diabetics, dialysis patients, transplant recipients, and cancer patients. Malignant tumors of the nails are often not correctly diagnosed at first. For subungual melanoma, the mean time from the initial symptom to the correct diagnosis is approximately 2 years; this delay is partly responsible for the low 10-year survival rate of only 43%.

CONCLUSION

Evaluation of the nail organ is an important diagnostic instrument. Aside from onychomycosis, which is a common nail disorder, important differential diagnoses such as malignant diseases, drug side effects, and bacterial infections must be considered.

Variability in Systemic Treatment Efficacy for Onychomycosis: Information That Clinical Studies Do Not Impart to the Office Dermatologist

Wide differences in the cure rates of onychomycosis in various clinical studies can be avoided if we bear in mind some insights that will help us make study results more consistent. We suggest less rigid criteria in defining the cure rate, the inclusion of all toenails in studies, and the exclusion of nails with a history of trauma. Rather than address patients as a homogenous group, regardless of age, we suggest dividing them into age groups. Researchers should not forget inflammatory diseases that can imply changes on the nails and should take into account the duration of onychomycosis, nail changes caused by asymmetry, and the possibility of dermatophytoma.

Onychomycosis in the 21st Century: An Update on Diagnosis, Epidemiology, and Treatment

Onychomycosis accounts for 50% of all nail disease cases and is commonly caused by dermatophytes. Diabetes, human immunodeficiency virus, immunosuppression, obesity, smoking, and advancing age are predisposing factors of this fungal infection. Potassium hydroxide and culture are considered the current standard for diagnosing onychomycosis, revealing both fungal viability and species identification. Other diagnostic tests currently available include periodic acid-Schiff staining, polymerase chain reaction techniques, and fluorescent staining. Across 6 recently published epidemiology studies, the global prevalence of onychomycosis was estimated to be 5.5%, falling within the range of previously reported estimates (2%-8%). Newly approved onychomycosis treatments include efinaconazole, tavaborole, and laser therapy with lasers only approved to temporarily increase the amount of clear nail. Additional onychomycosis treatments being investigated include iontophoresis and photodynamic therapy with small open-label studies reported thus far. Preventative strategies, to help decrease recurrence and reinfection rates, include sanitisation of footwear and prophylactic topical antifungal agents.

New Antifungal Agents and New Formulations Against Dermatophytes

A variety of oral and topical antifungal agents are available for the treatment of superficial fungal infections caused by dermatophytes. This review builds on the antifungal therapy update published in this journal for the first special issue on Dermatophytosis (Gupta and Cooper 2008;166:353-67). Since 2008, there have not been additions to the oral antifungal armamentarium, with terbinafine, itraconazole, and fluconazole still in widespread use, albeit for generally more severe or recalcitrant infections. Griseofulvin is used in the treatment of tinea capitis. Oral ketoconazole has fallen out of favor in many jurisdictions due to risks of hepatotoxicity. Topical antifungals, applied once or twice daily, are the primary treatment for tinea pedis, tinea corporis/tinea cruris, and mild cases of tinea unguium. Newer topical antifungal agents introduced include the azoles, efinaconazole, luliconazole, and sertaconazole, and the oxaborole, tavaborole. Research is focused on developing formulations of existing topical antifungals that utilize novel delivery systems in order to enhance treatment efficacy and compliance.

Improving Cure Rates in Onychomycosis

Background:

Onychomycosis is a persistent fungal nail infection that is notoriously hard to treat. Approximately 20% to 25% of patients with onychomycosis do not respond to treatment, and 10% to 53% of patients relapse. As such, successful treatment is imperative for long-term disease management.

Objective:

To identify ways to improve cure rates for onychomycosis.

Method:

The literature on onychomycosis treatment and recurrence was reviewed to summarize treatment approaches and suggest strategies to increase cure rates.

Results and Conclusion:

To improve treatment success in onychomycosis, we suggest the following measures be followed: (1) onychomycosis must be correctly diagnosed, (2) the treatment regimen should be tailored to the individual patient, (3) the efficacy of antifungals must be maximized, and (4) recurrence must be prevented.

Eficacia y seguridad de la terbinafina oral en pauta intermitente o pulsátil versus pauta continua para el tratamiento de la onicomicosis en mayores de 18 años

<p>La onicomicosis es una enfermedad que compromete las uñas y afecta el 5% de la población mundial. Objetivo. Determinar la efectividad y seguridad de la terbinafina oral en pauta intermitente versus continua para la onicomicosis en mayores de 18 años. Materiales y métodos. A través de una búsqueda sistemática electrónica en Cochrane, Medline, Embase, LILACS y Opengrey se identificaron ensayos clínicos aleatorizados paralelos, excluyendo cruzados, conglomerados o clúster. Se aplicó el RevMan 5.3 para revisiones sistemáticas de ensayos clínicos. Mediante búsqueda sistemática se identificaron ensayos clínicos aleatorizados paralelos en pacientes mayores de 18 años, de sexo masculino o femenino, humanos, en idioma inglés y español, sin límite de tiempo de publicación y cuyo desenlace fue la curación clínica y micológica, incluyendo efectos adversos leves. Se valoró el riesgo de sesgo; se utilizó RR como medida del efecto, IC95% para variables dicotómicas; la unidad de análisis fue el paciente y la estimación agrupada se calculó usando un modelo de efectos aleatorios para variables dicotómicas —método de Mantel-Haenszel en RevMan 5.3—. Resultados. El RR agrupado fue de 1.13 (IC95%: 1.06-1.2) indicando que la falla del tratamiento con terbinafina intermitente es 1.1 veces más probable que con terbinafina continua. Su RR agrupado dio 0.923 (IC95%: 0.77-1.09) indicando 7.7% de mayor probabilidad de desarrollar eventos adversos con terbinafina continua que con intermitente. Conclusiones. La terbinafina intermitente tiene menor éxito de cura clínica y micológica que la continua; su RR corregido demuestra que la pauta intermitente es 13% menos eficiente que la continua. Clínicamente los hallazgos son significativos pero estadísticamente falta poder en los estudios y un mayor tamaño de muestra agrupado para mejorar la evidencia.</p>

Mycology - an update Part 3: Dermatomycoses: topical and systemic therapy

Treatment of dermatophyte infections is based on the clinical picture and mycological detection of the causative pathogen. Based on the appropriate indication, onychomycosis can be treated topically using an antimycotic nail lacquer. Atraumatic nail abrasion with 40 % urea ointment has a beneficial effect on healing. Continuous treatment of onychomycosis with terbinafine represents the most effective systemic therapy. Terbinafine or itraconazole are the safest and most effective antimycotic agents for the treatment of onychomycosis in children. For laser therapy of onychomycosis, only a few studies on clinical efficacy are available. Regarding tinea capitis, targeted species-specific therapy of dermatophytosis of the scalp is currently recommended. Terbinafine, yet also itraconazole and fluconazole, are effective in tinea capitis caused by Trichophyton species. Microsporum infections of the scalp are preferably treated with griseofulvin, alternatively with itraconazole or fluconazole. Terbinafine is less effective. Candidal intertrigo are topically treated with nystatin, but azoles or ciclopirox olamine are also suitable candidates. Systemically, fluconazole or itraconazole are used. Topical and systemic antimycotics are equivalent forms of therapy in acute vulvovaginal mycosis. Fluconazole is the drug of choice in chronic recurrent vulvovaginal mycosis caused by Candida albicans. Ketoconazole shows very good efficacy in tinea versicolor. With respect to systemic treatment of severe and widespread tinea versicolor, itraconazole is the drug of choice.

Spotlight on tavaborole for the treatment of onychomycosis

Onychomycosis is a fungal nail plate infection that has been increasing in prevalence. A variety of oral and topical anti-fungal agents are currently available but their use is limited by their adverse effect profile, drug–drug interactions, and limited efficacy. Therefore, there is a great need for newer anti-fungal agents. Tavaborole is one of these newer agents and was approved by the US Food and Drug Administration in July 2014 for the topical treatment of mild to moderate toenail onychomycosis. Tavaborole is a novel, boron-based anti-fungal agent with greater nail plate penetration than its predecessors, due to its smaller molecular weight. It has proven through several Phase II and III trials that it can be a safe and effective topical agent for the treatment of mild to moderate toenail onychomycosis without the need for debridement. In this paper, we review the landscape of topical and systemic treatment of onychomycosis, with particular attention to the pharmacokinetics, safety, and efficacy of topical tavaborole.

Efinaconazole 10% topical solution for the topical treatment of onychomycosis of the toenail

Efinaconazole 10% topical solution is a new antifungal therapy for the topical treatment of mild to moderate toenail onychomycosis. In vitro and in vivo data have shown significant antifungal activity against dermatophytes, Candida spp. and nondermatophyte molds, and its mechanism of action is through inhibition of fungal lanosterol 14α-demethylase. In two parallel, double-blind, randomized, controlled, Phase III trials, complete cure rates were 17.8 and 15.2%, respectively, and mycological cure rates were 55.2 and 53.4%, respectively, for efinaconazole 10% topical solution, which were superior to vehicle, with minimal adverse events. This drug profile reviews the most recent basic science and clinical data for efinaconazole in the treatment of toenail onychomycosis.

Efinaconazole in the treatment of onychomycosis

Efinaconazole 10% topical solution is a new triazole recently approved for the treatment of onychomycosis. It inhibits fungal lanosterol 14α-demethylase in the ergosterol biosynthesis pathway, has potent antifungal activity against dermatophytes, as well as activity against Candida spp. and non-dermatophyte molds, and showed promising results in clinical trials. This review summarizes the mechanism of action, in vitro and in vivo data, clinical trials, safety, and quality-of-life data of efinaconazole as it applies to the treatment of onychomycosis.

Onychomycosis: A Review

Onychomycosis is the most common nail infective disorder. It is caused mainly by anthropophilic dermatophytes, in particular by Trichophyton rubrum and T. mentagrophytes var. interdigitale. Yeasts, like Candida albicans and C. parapsilosis, and molds, like Aspergillus spp., represent the second cause of onychomycosis. The clinical suspect of onychomycosis should be confirmed my mycology. Onychoscopy is a new method that can help the physician, as in onychomycosis, it shows a typical fringed proximal margin. Treatment is chosen depending on the modality of nail invasion, fungus species and the number of affected nails. Oral treatments are often limited by drug interactions, while topical antifungal lacquers have less efficacy. A combination of both oral and systemic treatment is often the best choice.

VT-1161 dosed once daily or once weekly exhibits potent efficacy in treatment of dermatophytosis in a guinea pig model

Current therapies used to treat dermatophytoses such as onychomycosis are effective but display room for improvement in efficacy, safety, and convenience of dosing. We report here that the investigational agent VT-1161 displays potent in vitro antifungal activity against dermatophytes, with MIC values in the range of ≤0.016 to 0.5 μg/ml. In pharmacokinetic studies supporting testing in a guinea pig model of dermatophytosis, VT-1161 plasma concentrations following single oral doses were dose proportional and persisted at or above the MIC values for at least 48 h, indicating potential in vivo efficacy with once-daily and possibly once-weekly dosing. Subsequently, in a guinea pig dermatophytosis model utilizing Trichophyton mentagrophytes and at oral doses of 5, 10, or 25 mg/kg of body weight once daily or 70 mg/kg once weekly, VT-1161 was statistically superior to untreated controls in fungal burden reduction (P < 0.001) and improvement in clinical scores (P < 0.001). The efficacy profile of VT-1161 was equivalent to those for doses and regimens of itraconazole and terbinafine except that VT-1161 was superior to itraconazole when each drug was dosed once weekly (P < 0.05). VT-1161 was distributed into skin and hair, with plasma and tissue concentrations in all treatment and regimen groups ranging from 0.8 to 40 μg/ml (or μg/g), at or above the MIC against the isolate used in the model (0.5 μg/ml). These data strongly support the clinical development of VT-1161 for the oral treatment of onychomycosis using either once-daily or once-weekly dosing regimens.

The prevalence of onychomycosis in the global population: a literature study

BACKGROUND

Onychomycosis is a common disorder, and high prevalence figures are commonly cited in the literature.

OBJECTIVES

Evaluate the prevalence of onychomycosis based on published studies.

METHODS

Relevant studies were identified in Medline by using specific search criteria.

RESULTS

Eleven population-based and 21 hospital-based studies were identified. The mean prevalence in Europe and North America was 4.3% [95% Confidence Interval (CI): 1.9-6.8] in the population-based studies, but it was 8.9% (95% CI: 4.3-13.6) for the hospital-based studies. Both population-based and hospital-based studies showed that onychomycosis is more common in toenails and is seen more frequently in males. The main causative agent was a dermatophyte in 65.0% (95% CI: 51.9-78.1) of the cases. Trichophyton rubrum was the single most common fungus and was cultured on average in 44.9% of the cases (95% CI: 33.8-56.0). Moulds were found on average in 13.3% (95% CI: 4.6-22.1) and yeasts in 21.1% (95% CI: 11.0-31.3).

LIMITATIONS

We may not have been able to locate all studies.

CONCLUSIONS

Onychomycosis is a common disorder, but it may not be as common as cited in the literature, because hospital-based studies might overestimate the prevalence of onychomycosis. It is more frequent in males, and toenails are more commonly affected. Dermatophytes, particularly T. rubrum, are the main causative agents.

Lamisil versus clotrimazole in the treatment of vulvovaginal candidiasis

BACKGROUND AND OBJECTIVES

Vaginal candidiasis is a common disease in women during their lifetime and occurs in diabetes patients, during pregnancy and oral contraceptives users. Although several antifungals are routinely used for treatment; however, vaginal candidiasis is a challenge for patients and gynecologists. The aim of the present study was to evaluate terbinafine (Lamisil) on Candida vaginitis versus clotrimazole.

MATERIALS AND METHODS

In the present study women suspected to have vulvovaginal candidiasis were sampled and disease confirmed using direct smear and culture examination from vaginal discharge. Then, patients were randomly divided into two groups, the first group (32 cases) was treated with clotrimazole and the next (25 cases) with Lamisil. All patients were followed-up to three weeks of treatment and therapeutic effects of both antifungal were compared.

RESULTS

Our results shows that 12 (37.5%) patients were completely treated with clotrimazole during two weeks and, 6(18.8%) patients did not respond to drugs and were refereed for fluconazole therapy. Fourteen (43.8%) patients showed moderate response and clotrimazole therapy was extended for one more week. When Lamisil was administrated, 19 (76.0%) patients were completely treated with Lamisil in two weeks, and 1 (4.0%) of the patients did not respond to the drug and was refereed for fluconazole therapy. Five (20.0%) of our patients showed moderate response and Lamisil therapy was extended for one more week.

CONCLUSION

Our results show that vaginal cream, 1% Lamisil, could be suggested as a first-line treatment in vulvovaginal candidiasis.