Ciclopirox Hydroxypropyl Chitosan: Efficacy in Mild-to-Moderate Onychomycosis

Onychomycosis: An Updated Review

Background: Onychomycosis is a common fungal infection of the nail.

Objective: The study aimed to provide an update on the evaluation, diagnosis, and treatment of onychomycosis.

Methods: A PubMed search was completed in Clinical Queries using the key term “onychomycosis”. The search was conducted in May 2019. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews published within the past 20 years. The search was restricted to English literature. Patents were searched using the key term “onychomycosis” in www.freepatentsonline.com.

Results: Onychomycosis is a fungal infection of the nail unit. Approximately 90% of toenail and 75% of fingernail onychomycosis are caused by dermatophytes, notably Trichophyton mentagrophytes and Trichophyton rubrum. Clinical manifestations include discoloration of the nail, subungual hyperkeratosis, onycholysis, and onychauxis. The diagnosis can be confirmed by direct microscopic examination with a potassium hydroxide wet-mount preparation, histopathologic examination of the trimmed affected nail plate with a periodic-acid-Schiff stain, fungal culture, or polymerase chain reaction assays. Laboratory confirmation of onychomycosis before beginning a treatment regimen should be considered. Currently, oral terbinafine is the treatment of choice, followed by oral itraconazole. In general, topical monotherapy can be considered for mild to moderate onychomycosis and is a therapeutic option when oral antifungal agents are contraindicated or cannot be tolerated. Recent patents related to the management of onychomycosis are also discussed.

Conclusion: Oral antifungal therapies are effective, but significant adverse effects limit their use.Although topical antifungal therapies have minimal adverse events, they are less effective than oral antifungal therapies, due to poor nail penetration. Therefore, there is a need for exploring more effective and/or alternative treatment modalities for the treatment of onychomycosis which are safer and more effective.

Ciclopirox Hydroxypropyl Chitosan (HPCH) Nail Lacquer: A Review of Its Use in Onychomycosis

Ciclopirox 8% hydroxypropyl chitosan (HPCH) [Marketed in different countries as the following registered (®) brands: Ciclopoli, Fulcare, Kitonail, Myconail, Niogermos, Niogermox, Onytec, Ony-Tec, Polinail, Privex, Rejuvenail] is the first topical nail lacquer developed using innovative drug formulation technology. It is indicated for the treatment of mild-to-moderate fungal infections of the nails that are caused by dermatophytes and/or other ciclopirox-sensitive fungi, without nail matrix involvement. HPCH is a patented drug formulation technology for the delivery of active principles into the nails based on a hydrosoluble semisynthetic amino-polysaccharide biopolymer derivative of chitosan. The lacquer acts as a protective barrier against microbiological attack, physical damage and/or aggressive chemicals. Results from in vitro studies suggest that the application of ciclopirox 8% HPCH nail lacquer improves drug permeation into and/or drug penetration through the nail, relative to the water-insoluble ciclopirox 8%, amorolfine 5% and efinaconazole 10% reference lacquers. In addition, in vitro and clinical studies in healthy subjects found that the concentration of ciclopirox reached in subungual fluids after application of ciclopirox 8% HPCH was sufficient for inhibiting fungal growth. In clinical studies in patients with mild-to-moderate onychomycosis, ciclopirox 8% HPCH was found to be more effective than the commercial water-insoluble ciclopirox 8% and amorolfine 5% lacquers, as indicated by higher complete cure, response and mycological cure rates at 48 weeks after treatment initiation. Ciclopirox 8% HPCH has been found to be generally well tolerated, with no treatment-related adverse events reported in patients using this nail lacquer. Thus, current evidence indicates that ciclopirox 8% HPCH represents a valuable treatment option for the treatment of patients with onychomycosis.

Methylene blue vs methyl aminolevulinate photodynamic therapy in the treatment of mild-to-moderate toenail onychomycosis: Short- and medium-term effects

Photodynamic therapy (PDT) has emerged as an interesting alternative option for onychomycosis treatment. The impact of a specific photosensitizer (PS) on the final result is an important factor to consider. We conducted a short- and medium-term controlled trial to compare the effectiveness of PDT in the treatment of mild-to-moderate onychomycosis when it is mediated by two different PSs. Twenty patients were randomized to receive nine sessions of PDT distributed over 16 weeks mediated either by methylene blue (MB/PDT group) or methyl aminolevulinate (MAL/PDT group). Onychomycosis severity index (OSI) and nail involvement were checked along the study. Complete cure, treatment success, and clinical improvement were tabulated at 16 and 40-week follow-ups. OSI scores decreased significantly along the study, from 12.1 ± 5.4 to 3.6 ± 3.2 (MB/PDT group) and from 14.8 ± 6.0 to 5.4 ± 4.4 (MAL/PDT group). At 16-week follow-up, only 20% of the patients in the MB/PDT group reached complete cure and none in the group of MAL/PDT. At 40-week follow-up, complete cure rates were 70% and 40% in the MB/PDT group and MAL/PDT group respectively. Both modalities showed good outcomes in treatment of moderate toenail onychomycosis. MB/PDT showed a faster action but with relapse rates slightly higher than MAL/PDT.

Onychomycosis in children - review on treatment and management strategies

BACKGROUND

Onychomycosis is an uncommon condition in children with increasing global prevalence. Health practitioners should confirm the diagnosis through mycology examination and examine family members of affected individuals for onychomycosis and tinea pedis.

OBJECTIVE

To comprehensively summarize the treatment and management strategies for pediatric onychomycosis.

METHODS

We performed a comprehensive literature search in the PubMed database to identify clinical studies on treatment for mycologically-confirmed dermatophyte onychomycosis in children <18 years. The exclusion criteria were combination therapy, case reports, reviews, systematic reviews and duplicate studies.

RESULTS

Per-weight dosing regimens of systemic antifungal agents such as terbinafine, itraconazole, and fluconazole are found to be safe in children and are used off-label for the treatment of pediatric onychomycosis with high efficacy. Topical antifungal agents such as ciclopirox, efinaconazole, and tavaborole have established safety and efficacy in children. Children respond better than adults to topical therapy due to their thinner, faster growing nails. There is no data on the efficacy of medical devices for onychomycosis in children.

CONCLUSION

Efinaconazole topical solution 10% and tavaborole topical solution 5% are FDA approved for the treatment of onychomycosis in children ≥6 years; ciclopirox topical solution 8% nail lacquer is approved in children ≥12 years.

Topical and device-based treatments for fungal infections of the toenails

BACKGROUND

Onychomycosis refers to fungal infections of the nail apparatus that may cause pain, discomfort, and disfigurement. This is an update of a Cochrane Review published in 2007; a substantial amount of new research warrants a review exclusively on toenails.

OBJECTIVES

To assess the clinical and mycological effects of topical drugs and device-based therapies for toenail onychomycosis.

SEARCH METHODS

We searched the following databases up to May 2019: the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase and LILACS. We also searched five trials registers, and checked the reference lists of included and excluded studies for further references to relevant randomised controlled trials.

SELECTION CRITERIA

Randomised controlled trials of topical and device-based therapies for onychomycosis in participants with toenail onychomycosis, confirmed by positive cultures, direct microscopy, or histological nail examination. Eligible comparators were placebo, vehicle, no treatment, or an active topical or device-based treatment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Primary outcomes were complete cure rate (normal-looking nail plus fungus elimination, determined with laboratory methods) and number of participants reporting treatment-related adverse events.

MAIN RESULTS

We included 56 studies (12,501 participants, average age: 27 to 68 years), with mainly mild-to-moderate onychomycosis without matrix involvement (where reported). Participants had more than one toenail affected. Most studies lasted 48 to 52 weeks; 23% reported disease duration (variable). Thirty-five studies specifically examined dermatophyte-caused onychomycosis. Forty-three studies were carried out in outpatient settings. Most studies assessed topical treatments, 9% devices, and 11% both. We rated three studies at low risk of bias across all domains. The most common high-risk domain was performance bias. We present results for key comparisons, where treatment duration was 36 or 48 weeks, and clinical outcomes were measured at 40 to 52 weeks. Based on two studies (460 participants), compared with vehicle, ciclopirox 8% lacquer may be more effective in achieving complete cure (risk ratio (RR) 9.29, 95% confidence interval (CI) 1.72 to 50.14; low-quality evidence) and is probably more effective in achieving mycological cure (RR 3.15, 95% CI 1.93 to 5.12; moderate-quality evidence). Ciclopirox lacquer may lead to increased adverse events, commonly application reactions, rashes, and nail alteration (e.g. colour, shape). However, the 95% CI indicates that ciclopirox lacquer may actually make little or no difference (RR 1.61, 95% CI 0.89 to 2.92; low-quality evidence). Efinaconazole 10% solution is more effective than vehicle in achieving complete cure (RR 3.54, 95% CI 2.24 to 5.60; 3 studies, 1716 participants) and clinical cure (RR 3.07, 95% CI 2.08 to 4.53; 2 studies, 1655 participants) (both high-quality evidence) and is probably more effective in achieving mycological cure (RR 2.31, 95% CI 1.08 to 4.94; 3 studies, 1716 participants; moderate-quality evidence). Risk of adverse events (such as dermatitis and vesicles) was slightly higher with efinaconazole (RR 1.10, 95% CI 1.01 to 1.20; 3 studies, 1701 participants; high-quality evidence). No other key comparison measured clinical cure. Based on two studies, compared with vehicle, tavaborole 5% solution is probably more effective in achieving complete cure (RR 7.40, 95% CI 2.71 to 20.24; 1198 participants), but probably has a higher risk of adverse events (application site reactions were most commonly reported) (RR 3.82, 95% CI 1.65 to 8.85; 1186 participants (both moderate-quality evidence)). Tavaborole improves mycological cure (RR 3.40, 95% CI 2.34 to 4.93; 1198 participants; high-quality evidence). Moderate-quality evidence from two studies (490 participants) indicates that P-3051 (ciclopirox 8% hydrolacquer) is probably more effective than the comparators ciclopirox 8% lacquer or amorolfine 5% in achieving complete cure (RR 2.43, 95% CI 1.32 to 4.48), but there is probably little or no difference between the treatments in achieving mycological cure (RR 1.08, 95% CI 0.85 to 1.37). We found no difference in the risk of adverse events (RR 0.60, 95% CI 0.19 to 1.92; 2 studies, 487 participants; low-quality evidence). The most common events were erythema, rash, and burning. Three studies (112 participants) compared 1064-nm Nd:YAG laser to no treatment or sham treatment. We are uncertain if there is a difference in adverse events (very low-quality evidence) (two studies; 85 participants). There may be little or no difference in mycological cure at 52 weeks (RR 1.04, 95% CI 0.59 to 1.85; 2 studies, 85 participants; low-quality evidence). Complete cure was not measured. One study (293 participants) compared luliconazole 5% solution to vehicle. We are uncertain whether luliconazole leads to higher rates of complete cure (very low-quality evidence). Low-quality evidence indicates there may be little or no difference in adverse events (RR 1.02, 95% CI 0.90 to 1.16) and there may be increased mycological cure with luliconazole; however, the 95% CI indicates that luliconazole may make little or no difference to mycological cure (RR 1.39, 95% CI 0.98 to 1.97). Commonly-reported adverse events were dry skin, paronychia, eczema, and hyperkeratosis, which improved or resolved post-treatment.

AUTHORS' CONCLUSIONS

Assessing complete cure, high-quality evidence supports the effectiveness of efinaconazole, moderate-quality evidence supports P-3051 (ciclopirox 8% hydrolacquer) and tavaborole, and low-quality evidence supports ciclopirox 8% lacquer. We are uncertain whether luliconazole 5% solution leads to complete cure (very low-quality evidence); this outcome was not measured by the 1064-nm Nd:YAG laser comparison. Although evidence supports topical treatments, complete cure rates with topical treatments are relatively low. We are uncertain if 1064-nm Nd:YAG laser increases adverse events compared with no treatment or sham treatment (very low-quality evidence). Low-quality evidence indicates that there is no difference in adverse events between P-3051 (ciclopirox hydrolacquer), luliconazole 5% solution, and their comparators. Ciclopirox 8% lacquer may increase adverse events (low-quality evidence). High- to moderate-quality evidence suggests increased adverse events with efinaconazole 10% solution or tavaborole 5% solution. We downgraded evidence for heterogeneity, lack of blinding, and small sample sizes. There is uncertainty about the effectiveness of device-based treatments, which were under-represented; 80% of studies assessed topical treatments, but we were unable to evaluate all of the currently relevant topical treatments. Future studies of topical and device-based therapies should be blinded, with patient-centred outcomes and an adequate sample size. They should specify the causative organism and directly compare treatments.

Recent advances in therapies for onychomycosis and its management

Onychomycosis is the most common affliction of the nail. It may be caused by dermatophytes, yeasts, and non-dermatophyte molds. Traditionally, oral antifungal treatments have been used to treat the fungus, although they can be accompanied by side effects and drug interactions. Topical treatments provide an alternative modality, bypassing the systemic effects of oral drugs; recent research has centered on topical drug improvement and development. Physical and laser treatments are being used in conjunction with topicals, which may help penetrate the thick nail plate. In this review, techniques from all categories are outlined: both novel experimental approaches and progress and effectiveness of recently developed treatments. More long-term studies are required to determine the efficacy of various treatments, but cure rates are improved when patients adhere to treatments and follow preventative measures to avoid disease recurrence.