The use of topical therapies to treat onychomycosis

Antifungal Selection for the Treatment of Onychomycosis: Patient Considerations and Outcomes

Onychomycosis, a common fungal nail infection, affects >20% of adults over age 60 and >50% of people over age 70. Onychomycosis may cause pain, psychosocial problems, and secondary infections, therefore meriting treatment. This review describes the range of treatment modalities, including FDA-approved systemic drugs and topical therapies. Additionally, new and emerging oral and topical therapies are discussed. We emphasize the importance of tailoring onychomycosis therapy to individual patient characteristics, comorbidities, preferences, extent of nail involvement, and fungal species, such that physicians may optimize treatment outcomes, patient satisfaction, and safety.

Therapeutic treatment strategies for the management of onychomycosis: a patent perspective

INTRODUCTION

Onychomycosis, a multifactorial fungal infection of the nails, shows a global prevalence of about 5.5% and is responsible for 50% of all nail infections. To develop effective management strategies, it is necessary to understand the etiology, pathophysiology, and risk factors of onychomycosis. Oral route of drug delivery is one of the routes utilized to deliver anti-fungal agents, but, has its own limitations like longer duration of treatment, increased adverse effects, and potential for drug interaction. The ungual route has received greater attention due to its localized, non- invasive action and improved patient compliance.

AREAS COVERED

This review comprehensively discusses conventional onychomycosis therapies and patented novel drug delivery systems for the management of onychomycosis including chemical permeation enhancers, non-particulate drug delivery systems, penetration enhancing devices etc., Databases such as PubMed, ResearchGate, and Google Patents were searched by using the keywords onychomycosis and trans-ungual drug delivery.

EXPERT OPINION

Enormous research has been conducted and is still ongoing to find the best possible novel drug delivery system for onychomycosis management. Approaches like incorporation of herbal constituents in nano-formulations, inkjet printing, laser devices, iontophoretic techniques, etc. can be employed to make safe and effective drug delivery systems which are regulatory compliant.

Combination Therapy Should Be Reserved as Second-Line Treatment of Onychomycosis: A Systematic Review of Onychomycosis Clinical Trials

Onychomycosis is the most common nail disease encountered in clinical practice. Its importance extends well beyond aesthetics, often causing pain, difficulty with ambulation and performing daily activities, and impairing quality of life. Many patients fail to achieve cure with antifungal monotherapy and recurrences are common. Combination therapy has therefore gained considerable interest, given the potential for drug synergy and prevention of antifungal resistance, but it has not been well studied. A systematic review of onychomycosis medication only, as well as medication and procedural (laser, debridement, photodynamic therapy), clinical or randomized controlled trials evaluating combination vs. monotherapies was performed. After exclusions, 30 studies were included in the final analysis. There were conflicting results for medication-only trials, with some showing significant benefit of combination therapy over monotherapy, however, trials were not robustly designed and lacked sufficient follow-up. Procedural studies also lacked long-term follow-up, and failed to demonstrate efficacy in some severe onychomycosis cases. Considering the high cure rates demonstrated in pivotal antifungal monotherapy trials, and conflicting results, costs, and safety concerns associated with combination therapy, we recommend that combination therapy be reserved as second-line treatment options in patients with poor prognostic factors or for those who failed monotherapy for onychomycosis.

Combined long-pulsed Nd-Yag laser and itraconazole versus itraconazole alone in the treatment of onychomycosis nails

Background: Oral antifungal therapies are effective for onychomycosis but it was complicated by systemic effects. Effective and safe therapy is needed to improve esthetic appearance of nails.Objective: The present study is an attempt to evaluate and compare the efficacy of of combined treatment of onychomycosis with 1,064-nm long-pulsed Nd-Yag laser and pulse itraconazole therapy versus pulse itraconazole alone.Methods: Thirty onychomycosis patients were divided into two groups: Groups I and II. Patients of Group I are treated by itraconazole pulse therapy. Patients of Group II received six laser sessions with long-pulsed Nd:Yag laser and itraconazole pulse therapy. The investigators rated clearance using "Onychomycosis Severity Index (OSI)", photographs, and mycology at 6 and 9 months after treatment.Results: Group I's clinical improvement response was excellent in two cases, good in six cases, moderate in five cases, and mild in two cases. Mycological improvement response was excellent in two cases, good in two cases, moderate in six cases, and mild in five cases (OSI before treatment was 13.4 ± 3.02 and after was 6.67 ± 3.6). Group II's clinical improvement response was excellent in 10, good in 3, moderate in 1, and mild in 1. Mycological improvement's response was excellent in two cases, good in two cases, moderate in six cases, and mild in five cases (OSI before treatment was 13.33 ± 3.11 and after was 5.07 ± 4.15). There were no adverse effects. The clinical response showed best results with Group II, but the mycological cure was equal in both groups.Conclusions: The use of combined long-pulsed Nd-Yag laser and itraconazole pulse therapy gives the best clinical results and patient's satisfaction.

Clinico-aetiologic profile of Onychomycoses in a tertiary care centre in northeast India

Onychomycosis refers to fungal nail infection. Despite a clearly diseased appearance, it is often deemed a merely cosmetic problem of relatively minor importance. However, it may result in much psychological or occupational turmoil, diminished self-esteem and resulting reluctance for public interaction. A wide number of factors determine the treatment outcome and its prevalence varies greatly. Our study was conducted between January 2011 and December 2014 in northeast India. Of 243 patients presenting with nail abnormalities, 158 (65%) were positively diagnosed by either direct microscopy or culture or both. A distal lateral subungual infection was the most predominant clinical pattern observed, and the most frequent aetiological agents were dermatophytes, of which Trichophyton rubrum was predominant.

Brief Treatment Guide for Onychomycosis

Most onychomycosis infections result from dermatophyte organisms and present as distal lateral subungual onychomycosis (DLSO). Mild to moderate infections may be effectively treated with topical lacquer medications; however, there is no general consensus on what constitutes mild infection. In general, mild infections involve relatively small areas of the nail plate without infection of the nail matrix or lunula. Characteristics such as nail thickness, the number of nails affected, and the degree of onycholysis will also be taken into account in the categorization of nail severity and may increase the severity to moderate or severe even where nail plate area involvement is low. Similarly, although an infection may be mild, for patients with underlying health issues such as diabetes or immunodeficiency, oral therapy may be recommended as it typically provides the higher treatment efficacy required by these conditions. Severe infections may be treated with oral antifungal agents or combinations of oral agents and oral antifungals or oral and topical lacquer antifungals. Débridement is a technique that may be used in nearly any degree of infection to aid treatment efficacy by reducing the burden of fungal infection. Other treatment issues discussed include superficial white onychomycosis, nondermatophyte mold infection, and infection prophylaxis. Treatment is discussed considering a dermatophyte infection of DLSO presentation, unless otherwise stated. Infections should be confirmed by laboratory culture to eliminate any other diagnosis. Therapy recommendations concentrate on those agents approved in Canada for onychomycosis: oral terbinafine, oral itraconazole, and ciclopirox 8% nail lacquer.

Efinaconazole 10% nail solution: a new topical treatment with broad antifungal activity for onychomycosis monotherapy

BACKGROUND

Topical therapies for onychomycosis are associated with less adverse events than systemic therapies, but poor nail penetration limits their efficacy. Consequently, an efinaconazole 10% nail solution was developed.

OBJECTIVE

To review the evidence supporting the usefulness of efinaconazole monotherapy in onychomycosis management.

METHODS

PubMed and clinicaltrials.gov databases and abstracts from the 2013 annual meeting of the American Academy of Dermatology were searched in April 2013 using the terms "efinaconazole," "IDP-108," and "KP-103."

RESULTS

In vitro, efinaconazole possesses a broad antifungal activity similar or superior to that of other antifungals. Its low affinity for keratin results in good nail penetration. Efinaconazole 10% nail solution administered daily for 36 or 48 weeks to treat mild to moderate toenail onychomycosis caused by dermatophytes results in complete and mycologic cure rates of 15 to 25% and 53 to 87%, respectively. No serious skin reaction is associated with its use.

CONCLUSION

Efinaconazole 10% nail solution is a promising new treatment for onychomycosis.

Emerging therapies for the treatment of ungual onychomycosis

INTRODUCTION

Onychomycosis, a common fungal infection in the finger and toe nails, affects approximately 2-8% of the worldwide population. Fungal infection is more complicated in those who suffer from conditions, such as diabetes, peripheral vascular diseases and compromised immune diseases.

AREA COVERED

Onychomycosis treatment has been classified on the basis of location of infection in the toes and fingers and infectious agents (dermatophytes fungi, yeast and non-dermatophyte molds). In this review, the available therapies (traditional and device based) and their limitations for the treatment of onychomycosis have been discussed.

EXPERT OPINION

The success rate with topical nail products has been minimal. The main reason for this poor success rate could be attributed to the lack of complete understanding of the pathophysiology of the disease and clinical pharmacokinetic data of drugs in the infected nail apparatus.

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.

Amorolfine vs. ciclopirox - lacquers for the treatment of onychomycosis

Amorolfine 5% and ciclopirox 8% nail lacquers are commonly used in topical treatment of onychomycosis. These formulations may be used alone or in combination with oral antifungal agents. Amorolfine and ciclopirox are valuable therapeutic options, however, their usage in monotherapy should be limited. Proper amorolfine and ciclopirox penetration through the nail plate is provided by transungual drug delivery systems. Although amorolfine and ciclopirox have a different mode of action, they both exhibit a broad antifungal activity. The use of antifungal nail lacquers in combination with oral agents, such as terbinafine and itraconazole, improves efficacy of antifungal therapy.

Antifungal therapy for onychomycosis in children

Onychomycosis is a chronic infection of the nail unit, and its prevalence increases with age. Treatment options for children are similar to those for adults and include both oral and topical therapies. Oral agents, such as terbinafine, itraconazole, and fluconazole have been reported to have good efficacy and a low rate of side effects in children. Topical therapies, such as amorolfine and ciclopirox, can also be used as monotherapy or combined with oral agents to treat onychomycosis. Due to their thinner, faster-growing nails, children are more likely to respond to topical monotherapy than adults. There is currently insufficient data comparing emerging medical devices, such as laser therapy, with standard therapeutic options to recommend their use in children.

Potential role of tavaborole for the treatment of onychomycosis

ABSTRACT 

Systemic antifungal treatments are believed to be more effective than topicals for the treatment of onychomycosis; however, they are associated with more risks of adverse events. Tavaborole is the first member of a new class of antifungals that has been developed as a new topical nail solution for the treatment of toenail onychomycosis caused by dermatophytes. During Phase I–III clinical trials, tavaborole 5.0% nail solution showed a favorable safety and efficacy profile. Tavaborole 5.0% received US FDA market approval on 8 July 2014.

Infected nail plate model made of human hair keratin for evaluating the efficacy of different topical antifungal formulations against Trichophyton rubrum in vitro

A novel model of infected nail plate for testing the efficacy of topical antifungal formulations has been developed. This model utilized keratin film made of human hair keratin as a nail plate model. Subsequent to infection by Trichophyton rubrum, the common causative agent of onychomycosis, keratin films as infected nail plate models were treated with selected topical formulations, that is cream, gel, and nail lacquer. Bovine hoof was compared to keratin film. In contrast to the common antifungal susceptibility test, the antifungal drugs tested were applied as ready-to-use formulations because the vehicle may modify and control the drug action both in vitro and in vivo. Extrapolating the potency of an antifungal drug from an in vitro susceptibility test only would not be representative of the in vivo situation since these drugs are applied as ready-to-use formulations, for example as a nail lacquer. Although terbinafine has been acknowledged to be the most effective antifungal agent against T. rubrum, its antifungal efficacy was improved by its incorporation into an optimal formulation. Different gels proved superior to cream. Therefore, this study is able to discriminate between efficacies of different topical antifungal formulations based on their activities against T. rubrum.

An update on treatment of onychomycosis

Onychomycosis (OM) is a fungal infection of the nail plate or nail bed which is highly prevalent in the general population and also responsible for significant morbidity. The condition needs to be treated in view of the physical and emotional handicap it produces. The peculiarities of the nail apparatus in health and disease lead to difficulties in being able to successfully treat this condition. Hence, the very same antifungals which produce high cure rates in skin infections are rendered less efficacious in nail disease. Low cure rates and high relapse rates even with highly efficacious antifungals have lead to an increasing interest in exploring newer treatment options which can ensure drug penetration, drug persistence, mycological cure and effective prevention of relapse. The current review aims to summarize our current status of knowledge about the treatment options for OM. It also summarizes the newer areas of research especially with respect to devices related therapies; physical measures to enhance penetration through nail; and development and evaluation of synergistic combinations.

[Antifungal agents for onychomycoses]

Nail fungal infections are considered one of the major dermatological problems due to their high rate of therapeutic failure, management and treatment difficulties. Long-term treatments, inadequate therapies, mycological misdiagnosis and follow-up, secondary alterations of the nail, and resistant microorganisms, are some of the causes of these complications. Although the discovery of new antifungal agents has provided some effective molecules, none of the current available drugs are totally effective. It is important to continue researching in this field to provide new antifungal agents and combined therapies.

Combination of oral terbinafine and topical ciclopirox compared to oral terbinafine for the treatment of onychomycosis

BACKGROUND

Treatment of onychomycosis has recently been enhanced by the introduction of combination therapies.

OBJECTIVE

To evaluate the efficacy of a combination therapy of ciclopirox nail lacquer and oral terbinafine compared to oral terbinafine monotherapy for the treatment of onychomycosis caused by dermatophytes.

PATIENTS AND METHODS

Eighty patients with onychomycosis were randomly assigned to receive either oral terbinafine 250 mg/day for 16 weeks or a combination of oral terbinafine 250 mg/day for 16 weeks and topical ciclopirox nail lacquer once daily for 9 months. Both groups were followed up for 9 months from start of treatment.

RESULTS

After 9 months of treatment, the mycological cure rates were 22/34 (64.7%) for the terbinafine-only group and 30/34 (88.2%) for the combination therapy group (p<0.05). No significant difference was noted in the complete cure rate.

CONCLUSION

Combination therapy of oral terbinafine and ciclopirox nail lacquer is a safe and more effective treatment for onychomycosis than terbinafine alone, especially in younger patients and in shorter-duration onychomycosis.

Combination therapy consisting of week pulses of oral terbinafine plus topical application of terbinafine cream in the treatment of onychomycosis

BACKGROUND

Terbinafine, based on its pharmacokinetic properties, is a good candidate for pulse therapy. There are, as yet, no current guidelines for a terbinafine 1-week pulse regimine.

OBJECTIVE

To determine the optimal 1-week pulse dosing regimen for combination therapy of oral terbinafine with complementary 1% terbinafine cream for the treatment of onychomycosis.

DESIGN

A total of 69 onychomycosis patients received 250 mg terbinafine, given orally once daily for 7 days as 1-week pulses, separated by intervals of 2-3 weeks, until the desired improvement was observed. A daily application of 1% terbinafine cream was advised through to the evaluation date at 12 months follow-up. The treatment regimens were compared based on the number of pulses and the duration of treatment.

RESULTS

The 45 patients (65.2%) who achieved complete cure received an average of 7.8+/-3.5 pulse treatments over 4.8+/-2.6 months. The optimal terbinafine dosing regimen consisted of alternate 1-week pulses, with most patients on this regimen (19/20 cases; 95%) achieving total cure.

CONCLUSION

Favorable treatment outcome was gained from this terbinafine 1-week pulse regimen and also better compliance compared with a standard daily regimen.

Infection in the elderly

Many functional, demographic, and immunologic changes associated with aging are responsible for increasing the incidence and severity of infectious diseases in the elderly. Management is complicated by age-related organ system changes. Because many of the elderly are on multiple medications for underlying illnesses, antimicrobial therapy needs to be chosen keeping drug interactions and adverse events in mind. Common infections seen in the elderly are infections of skin and soft tissue, urinary tract, respiratory tract, and gastrointestinal tract. Organized and well-funded programs to address infectious disease issues in the elderly are the only way to improve care.

Recent progress on the topical therapy of onychomycosis

Onychomycosis is a fungal infection of the fingernails and toenails that results in thickening, discoloration, splitting of the nails and lifting of the nail from the nail bed. The disease is caused by dermatophytes and has a high incidence within the general population, especially among older individuals. Present treatment options include both oral and topical drugs, with oral therapies giving better outcomes; however, neither of these treatment options provides high cure rates that are durable. The difficulty in treating onychomycosis results from the deep-seated nature of the infection within the nail unit (nail plate, nail bed and surrounding tissue) and the inability of drugs to effectively reach all sites. Ongoing drug development activities have focused on novel delivery technologies to facilitate penetration of existing antifungal drugs through the nail plate and on the discovery of inherently penetrable antifungals. AN-2690 represents an oxaborole antifungal that is designed to penetrate the nail plate and is showing promising results in clinical trials.

Physicochemical studies on Ciclopirox olamine complexes with divalent metal ions

Ciclopirox olamine (CPO) metal complexes have been prepared and characterized using elemental analysis, infra red (IR), melting point and differential scanning calorimetry (DSC). Spectroscopic titration using molar ratio method indicated the occurrence of 1:1 complexes for CPO with almost all the examined metals. Physicochemical properties were also studied including aqueous solubility and apparent partition coefficient. Results showed that generally complex formation dramatically decreased the solubility and increased apparent partition coefficient. However, some metal complexes exhibited opposite effect. It could be concluded that complex formation can modify the solubility and apparent partition coefficient, which may suggest the use of complexes to manipulate the physicochemical properties of the drug.

Superficial fungal infections: an update on pityriasis versicolor, seborrheic dermatitis, tinea capitis, and onychomycosis

The recent advances in pityriasis versicolor, seborrheic dermatitis, tinea capitis and onychomycosis are reviewed. Some highlighted points include the new classification of Malassezia species, and the association of Malassezia species with seborrheic dermatitis. The use of terbinafine, fluconazole, and itraconazole for the treatment of tinea capitis is discussed. The management of onychomycosis, highlighting the high efficacy rates obtained with terbinafine when used to treat dermatophyte toenail onychomycosis, is discussed. The use of combination therapies in some circumstances to maximize cure rates is reviewed.