Treatment of onychomycosis: a randomized, double-blind comparison study with topical bifonazole-urea ointment alone and in combination with short-duration oral griseofulvin

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.

Race reporting and representation in onychomycosis clinical trials: A systematic review

BACKGROUND

Onychomycosis is the most common nail disease seen in clinical practice. Inclusion of diverse groups in onychomycosis clinical trials subjects is necessary to generalise efficacy data.

OBJECTIVES

We aimed to systematically review race and ethnicity reporting and representation, as well as, treatment outcomes in onychomycosis clinical trials.

METHODS

A PubMed search for onychomycosis clinical trials was performed in August 2020. Primary clinical trial data were included and post hoc analyses were excluded. Categorical variables were compared using chi-squared and Fisher's exact tests. Statistical significance was set at p < .05. Photos in articles were categorised by Fitzpatrick skin type.

RESULTS

Only 32/182 (17.5%) trials reported on race and/or ethnicity and only one trial compared treatment efficacy in different subgroups. Darker skin colours were infrequently depicted in articles. Topical treatment, location with ≥1 US-based site, industry funding type and publication date after 2000 were significantly associated with reporting of racial/ethnic data (p < .05 for all comparisons).

LIMITATIONS

Demographics on excluded subjects and methods of recruitment were not available. Assigning Fitzpatrick skin type is inherently subjective.

CONCLUSIONS

This study highlights a need for consistent reporting of races and ethnicities of onychomycosis clinical trial participants with subgroup analyses of treatment efficacies.

Urea-containing topical formulations

Urea is a well-known moisturiser and keratolytic topical agent. As it is widely used in dermatology, several formulations at different concentrations have been marketed: lotions, creams, foams, ointments, gels and lacquers. Availability of different vehicles and concentration may vary in different countries, but in general products at low, medium and high urea concentration are accessible worldwide. The proper formulation should be chosen according to the disorder to treat, its severity, body areas involved and patients' preference.

Once Weekly Application of Urea 40% and Bifonazole 1% Leads to Earlier Nail Removal in Onychomycosis

Introduction

Onychomycosis is a chronic nail fungal infection resulting in nail damage and a decreased quality of life. Chemical avulsion of the nail with urea and bifonazole -removes fungally infected debris, increasing antifungal treatment efficacy and penetration. Previous clinical ob-servations describe patients who applied their urea and -bifonazole ointment less frequently, achieving earlier nail removal. In this study, we analyzed the relationship between duration of urea and bifonazole application and time to nail avulsion.

Methods

χ² tests, multiple regression analysis, and ANOVA were performed to analyze the similarities between treatment regimens (daily, every 3 days, or once a week), association of regimens or patient characteristics to nail removal, and compare time to nail removal between each regimen, respectively.

Results

Daily application of ointment and sealing resulted in an average length of time (±SD) to nail removal of 18.7 days (±6.8 days); once every 3 days resulted in nail removal at 12.7 days (±6.2 days) and once per week at 11 days (±4.46 days) (p < 0.001). Age was the only patient factor that affected duration to nail removal.

Conclusion

Once weekly application of ointment with sealing for a 1-week duration is associated with a decrease in time to complete chemical avulsion of the nail by approximately 1 week.

Therapy of Skin, Hair and Nail Fungal Infections

Treatment of superficial fungal infections has come a long way. This has, in part, been through the development and evaluation of new drugs. However, utilising new strategies, such as identifying variation between different species in responsiveness, e.g., in tinea capitis, as well as seeking better ways of ensuring adequate concentrations of drug in the skin or nail, and combining different treatment methods, have played equally important roles in ensuring steady improvements in the results of treatment. Yet there are still areas where we look for improvement, such as better remission and cure rates in fungal nail disease, and the development of effective community treatment programmes to address endemic scalp ringworm.

Patient-reported outcomes from two randomised studies comparing once-weekly application of amorolfine 5% nail lacquer to other methods of topical treatment in distal and lateral subungual onychomycosis

Patient adherence is a key consideration in the choice of a topical regimen for the treatment of onychomycosis. The objective of this study was to investigate patient-reported outcomes (treatment utilisation, adherence and satisfaction) in onychomycosis treated with once-weekly amorolfine 5% nail lacquer versus once-daily ciclopirox 8% nail lacquer (Study A) or once-daily urea 40% ointment/bifonazole 1% cream combination regimen (Study B). Study A: Subjects received amorolfine and ciclopirox on opposite feet for 12 weeks. Study B: Subjects received amorolfine and urea/bifonazole on opposite feet for 6-7 weeks. Assessments included subject adherence as per label, treatment preference and questionnaire. Study A: More subjects adhered to amorolfine (85%) than to ciclopirox (60%) (P = .025). Overall, subjects were satisfied (95% vs 100%, respectively) and the treatments were balanced in terms of preference (50% vs 45%) at week 12. Study B: More subjects adhered to amorolfine dosage (81.8%) than to the dosage of the urea/bifonazole combination regimen (59.1%) (P = .096). At the end of study, 85.7% of subjects preferred amorolfine versus 14.3% for urea/bifonazole. Fewer subjects experienced local side effects with amorolfine (4.5%) compared to urea (27.3%) and bifonazole (15%). Amorolfine 5% nail lacquer offers a simple and convenient treatment option, which may result in improved patient adherence and consequently lead to improved efficacy and patient satisfaction.

Topical treatments for fungal infections of the skin and nails of the foot

BACKGROUND

Fungal infections of the feet normally occur in the outermost layer of the skin (epidermis). The skin between the toes is a frequent site of infection which can cause pain and itchiness. Fungal infections of the nail (onychomycosis) can affect the entire nail plate.

OBJECTIVES

To assess the effects of topical treatments in successfully treating (rate of treatment failure) fungal infections of the skin of the feet and toenails and in preventing recurrence.

SEARCH STRATEGY

We searched the Cochrane Skin Group Specialised Register (January 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2005), MEDLINE and EMBASE (from inception to January 2005). We screened the Science Citation Index, BIOSIS, CAB - Health and Healthstar, CINAHL DARE, NHS Economic Evaluation Database and EconLit (March 2005). Bibliographies were searched.

SELECTION CRITERIA

Randomised controlled trials (RCTs) using participants who had mycologically diagnosed fungal infections of the skin and nails of the foot.

DATA COLLECTION AND ANALYSIS

Two authors independently summarised the included trials and appraised their quality of reporting using a structured data extraction tool.

MAIN RESULTS

Of the 144 identified papers, 67 trials met the inclusion criteria. Placebo-controlled trials yielded the following pooled risk ratios (RR) of treatment failure for skin infections: allylamines RR 0.33 (95% CI 0.24 to 0.44); azoles RR 0.30 (95% CI 0.20 to 0.45); ciclopiroxolamine RR 0.27 (95% CI 0.11 to 0.66); tolnaftate RR 0.19 (95% CI 0.08 to 0.44); butenafine RR 0.33 (95% CI 0.24 to 0.45); undecanoates RR 0.29 (95% CI 0.12 - 0.70). Meta-analysis of 11 trials comparing allylamines and azoles showed a risk ratio of treatment failure RR 0.63 (95% CI 0.42 to 0.94) in favour of allylamines. Evidence for the management of topical treatments for infections of the toenails is sparser. There is some evidence that ciclopiroxolamine and butenafine are both effective but they both need to be applied daily for prolonged periods (at least 1 year). The 6 trials of nail infections provided evidence that topical ciclopiroxolamine has poor cure rates and that amorolfine might be substantially more effective but more research is required.

AUTHORS' CONCLUSIONS

Placebo-controlled trials of allylamines and azoles for athlete's foot consistently produce much higher percentages of cure than placebo. Allylamines cure slightly more infections than azoles and are now available OTC. Further research into the effectiveness of antifungal agents for nail infections is required.

Toenail onychomycosis: current and future treatment options

Onychomycosis is a common disease affecting as much as 8% of the general population. Treatment of onychomycosis is challenging, complicated by low cure rates and relatively high relapse rates. This paper reviews the efficacy of current oral, topical, and surgical treatment options. Currently, the treatment of choice for toenail onychomycosis is oral terbinafine because of its high efficacy, low relapse rates, and cost-effectiveness. Oral itraconazole or fluconazole could be considered for infections caused by Candida. Topical therapies may be a useful adjunct to these systemic therapies, but are less effective when used alone. More research is needed to determine the best measures for preventing reinfection.

Common Fungal Infections of the Feet in Patients with Diabetes Mellitus

Superficial fungal infections of the foot (tinea pedis and onychomycosis) are common among elderly patients. Although most authorities believe that patients with diabetes mellitus have an increased predisposition to dermatophytic infections, some controversies still remain. Because these infections disrupt the skin integrity and provide an avenue for bacterial superinfection, elderly diabetic patients with dermatophytic infection should be promptly treated with an antifungal agent. For most dermatophytic infections of the foot, topical agents are usually effective and less expensive than oral agents. Laboratory diagnosis of fungal infection prior to institution of therapy is recommended. Proper technique for obtaining the specimen is important to ensure a higher chance of isolating the infecting fungus. Commonly used anti-dermatophytic agents that are also active against the yeasts include the imidazoles, the allylamines-benzylamines and the hydroxypyridones, which are also effective against most of the moulds. Oral therapy for tinea pedis, although not well studied, should be limited to patients with more extensive infections, such as vesicobullous and moccasin type, resistant infections or chronic infections. In addition, oral agents should also be considered in diabetic and immunosuppressed patients. On the other hand, treatment of onychomycosis of the foot usually requires systemic therapy. Griseofulvin is the least effective agent when compared with the newer agents. Terbinafine, itraconazole and fluconazole have been shown to have acceptable cure rates. More recently, topical treatment of the nail with 8% ciclopirox nail lacquer, bifonazole with urea and amorolfine have been reported to be successful. Over the past decade, fungal foot infections of the skin and nail are more effectively treated with the introduction of numerous topical and oral agents.

The use of topical therapies to treat onychomycosis

The management of onychomycosis using topical agents has improved with the introduction of ciclopirox and amorolfine nail lacquers; other topical agents may be less effective. The combination of a nail lacquer with an oral antifungal agent may further improve efficacy rates in certain clinical presentations (eg, among those individuals with severe onychomycosis). Topical agents have a favorable adverse events profile. Further studies are required on the treatment of onychomycosis with nail lacquers.

Pharmacokinetics of antifungal agents in onychomycoses

Onychomycosis is caused by infection by fungi, mainly dermatophytes and nondermatophyte yeasts or moulds; it affects the fingernails and, more frequently, the toenails. Dermatophytes are responsible for about 90 to 95% of fungal infections. Trichophyton rubrum is the most common dermatophyte; Candida albicans is the major nondermatophyte yeast. Although topical therapy of onchomycosis does not lead to systemic adverse effects or interactions with concomitantly taken drugs, it does not provide high cure rates and requires complete compliance from the patient. At present there are 3 oral antifungal medications that are generally used for the short term treatment of onychomycosis: itraconazole, terbinafine and fluconazole. The persistence of these active drugs in nails allows weekly administration, reduced treatment or a pulse regimen. Good clinical and mycological efficacies are obtained with itraconazole 100 to 200 mg daily, terbinafine 250mg daily for 3 months, or fluconazole 150 mg weekly for at least 6 months. Itraconazole is a synthetic triazole with a broad spectrum of action. It is well absorbed when administered orally and can be detected in nails 1 to 2 weeks after the start of therapy. The nail : plasma ratio stabilises at around 1 by week 18 of treatment. Itraconazole is still detectable in nails 27 weeks after stopping administration. Nail concentrations are higher than the minimum inhibitory concentration (MIC) for most dermatophytes and Candida species from the first month of treatment. The elimination half-life of itraconazole from nails is long, ranging from 32 to 147 days. Terbinafine is a synthetic allylamine that is effective against dermatophytes. Terbinafine is well absorbed from the gastrointestinal tract, and the time to reach effective concentrations in nail is 1 to 2 weeks. The half-life is from 24 to 156 days, explaining the observed persistence of terbinafine in nails for longer than 252 days. Fluconazole is a bis-triazole broad spectrum antifungal with high oral bioavailability. The uptake of fluconazole by nail increases with the length of treatment, and nail : plasma ratios are generally 1.5 to 2 at steady state. Fluconazole concentrations exceed the MIC for Candida species soon after the start of treatment. Fluconazole concentrations fall slowly after the drug is stopped, with a half-life of 50 to 87 days, and fluconazole is still detectable in nails 5 months after the end of treatment. All these drugs are potent inhibitors of cytochrome P450 (CYP) enzymes and may increase the plasma concentrations of concomitantly used drugs. Itraconazole inhibits CYP3A4. Fluconazole inhibits CYP3A4, but to a lesser degree than itraconazole, CYP2C9 and CYP2C19. Terbinafine inhibits CYP2D6.

Treatment of toenail onychomycosis with 2% butenafine and 5% Melaleuca alternifolia (tea tree) oil in cream

The prevalence of onychomycosis, a superficial fungal infection that destroys the entire nail unit, is rising, with no satisfactory cure. The objective of this randomized, double-blind, placebo-controlled study was to examine the clinical efficacy and tolerability of 2% butenafine hydrochloride and 5% Melaleuca alternifolia oil incorporated in a cream to manage toenail onychomycosis in a cohort. Sixty outpatients (39 M, 21 F) aged 18-80 years (mean 29.6) with 6-36 months duration of disease were randomized to two groups (40 and 20), active and placebo. After 16 weeks, 80% of patients using medicated cream were cured, as opposed to none in the placebo group. Four patients in the active treatment group experienced subjective mild inflammation without discontinuing treatment. During follow-up, no relapse occurred in cured patients and no improvement was seen in medication-resistant and placebo participants.

Management of toenail onychomycosis with 2% butenafine and 20% urea cream: a placebo-controlled, double-blind study

Onychomycosis is an increasingly common and recalcitrant fungal nail infection world-wide. The purpose of this placebo-controlled, double-blind study was to determine the clinical efficacy, chemical avulsion, and tolerability of 2% butenafine hydrochloride and 20% urea incorporated in a cream to cure toenail onychomycosis in a preselected population. Sixty patients (38M, 22F), ranging between 18 and 60 years (mean 27.4), with more than 25% involvement of the big toenail were enrolled in the study. The diagnosis of onychomycosis was established by mycologic identification and reconfirmed by positive fungal culture. A precoded 25-g tube was randomly assigned to each patient (50 active and 10 placebo) with instructions to apply the trial medication to their infected toenail twice daily with an occlusive dressing for one week. The affected nail was removed with a nail clipper. No occlusive dressing was maintained after the initial one week regimen. To assess the chemical avulsion of the infected toenail, mycologic cure, clinical effectiveness of the treatment, and overall success, patients were examined twice a week for 16 weeks and thereafter on a weekly basis for a further 36 weeks. The treatment was well tolerated by all the patients throughout the study, with no dropouts. Marked improvement was seen in 73.3% patients after weeks 8, 16 and 24 with clinically and mycologically confirmed negative fungal culture. Code disclosure revealed that active butenafine and urea cream cured significantly more patients than placebo (88% versus 0%; p < 0.0001). Of the 60 patients 91.6% reported no drug-related adverse symptoms. Five patients reported non-objective mild inflammation without discontinuation of the treatment. During one year follow-up of the study phase, none of the cured patients had a relapse. In conclusion, the mycologic and overall assessment of this study demonstrate that 2% butenafine HCl and 20% urea incorporated in a cream for keratinolysis is safe to use and significantly more effective than placebo in curing big toenail onychomycosis.