An open randomized comparative study to test the efficacy and safety of oral terbinafine pulse as a monotherapy and in combination with topical ciclopirox olamine 8% or topical amorolfine hydrochloride 5% in the treatment of onychomycosis

In vitro determination of the combination of ciclopirox and terbinafine in the treatment of dermatophytosis

INTRODUCTION

The cases of dermatophytosis are increasing and they are associated with a higher number of therapeutic failures leading the doctor to prescribe combinations of antifungals as therapy. The objective was to evaluate the interaction of terbinafine and ciclopirox, the most commonly antifungals used in the clinic, in dermatophyte isolates.

METHODOLOGY

The minimum inhibitory concentrations (MIC) of ciclopirox and terbinafine were determined by the broth microdilution method according CLSI and the checkerboard assay was used to evaluate the interaction between the antifungal agents.

RESULTS

For terbinafine the mic50 was 0.125 ug/mL and mic90 was 0.250 ug/mL. For ciclopirox the values were 2.0 ug/mL for mic50 and 4.0 ug/mL for mic90. No synergistic interaction was observed for the dermatophyte isolates tested.

CONCLUSION

These results suggest that the use of terbinafine in combination with ciclopirox, which is widely used in the clinic, may not be a good choice for the treatment of onychomycosis.

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.

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.

Treatment, prevention and public health management of impetigo, scabies, crusted scabies and fungal skin infections in endemic populations: a systematic review

We conducted a systematic review of the treatment, prevention and public health control of skin infections including impetigo, scabies, crusted scabies and tinea in resource‐limited settings where skin infections are endemic. The aim is to inform strategies, guidelines and research to improve skin health in populations that are inequitably affected by infections of the skin and the downstream consequences of these. The systematic review is reported according to the PRISMA statement. From 1759 titles identified, 81 full text studies were reviewed and key findings outlined for impetigo, scabies, crusted scabies and tinea. Improvements in primary care and public health management of skin infections will have broad and lasting impacts on overall quality of life including reductions in morbidity and mortality from sepsis, skeletal infections, kidney and heart disease.

Evidence for biofilms in onychomycosis

Onychomycosis is a difficult to treat fungal infection of the nails. The chronic nature of onychomycosis contributes to high recurrence rates and the difficulty in treating both dermatophyte and non-dermatophyte infections. It has been hypothesized that the formation of biofilms, sessile, multicellular communities of fungi surrounded by a protective extracellular matrix, allow for fungi to evade current antifungal therapies and contribute to observed antifungal resistance. This review presents the experimental evidence that has accumulated in recent years implicating biofilms in the pathogenesis of onychomycosis. Dermatophytes, non-dermatophyte molds, and yeasts form biofilms in vitro and a model using ex vivo healthy nail fragments has demonstrated biofilm formation on nails for dermatophyte, Candida, and Fusarium species. Implications for disease management are discussed with further research required to incorporate biofilm formation into future drug/device evaluation and treatment protocols.

COMBINATION ANTIFUNGAL THERAPY FOR ONYCHOMYCOSIS

Onychomycosis is a fungal infection of the nail unit including the nail matrix, the nail bed and the nail plate by both dermatophyte and non-dermatophyte agents. It is disturbs not only cosmetic disfigurement, but also it may have an impact on patients’ emotional, social and occupational functioning, finally affecting the overall quality of life. The incidence rate tends to increase, management of onychomycosis is still challenging. Important problems regarding antifungal monotherapy have experienced many failures and recurrences. In general, pharmacological approaches for onychomycosis can be topical or oral antifungal. Antifungal monotherapies often lead to failure treatment, also high incidence of recurrence. One strategy for this problem is a combination antifungal therapy. In vitro studies show the synergistic effect of using combination two antifungals (both oral antifungal or combination topical and oral antifungal), hence it is mycologically or clinically expected to increase the success rate of onychomycosis therapy. This review tries to evaluate the previous study exploring the effectiveness of antifungal combination therapies on onychomycosis. Two oral antifungals usually used are terbinafine as fungicidal agent and itraconazole as fungistatic agent. There is combination between topical and oral antifungal such as itraconazole or terbinafine with amorolfine or ciclopirox, also other combination like griseofulvin and amorolfone or tioconazole. All the combination therapies show better result than monotherapy alone, but it is still difficult to conclude whether antifungal combinations in onychomycosis will increase effectiveness due to variations in therapeutic duration, result definition, and statistical evaluation on existing studies. Further research is required with longer duration of observation, uniform patient criteria and definition of success, random control and blinding to minimize bias.

A Retrospective Study Comparing K101 Nail Solution as a Monotherapy and in Combination with Oral Terbinafine or Itraconazole for the Treatment of Toenail Onychomycosis

Background

Onychomycosis is a difficult-to-treat fungal infection of the nails. The efficacy of monotherapy is not ideal, and combination therapies provide an alternative that may increase treatment efficacy.

Method

A retrospective analysis of data from 91 patients was undertaken. Treatment for toenail onychomycosis occurred between 2014 and 2016 and consisted of combination therapy with oral terbinafine (250 mg/day for 12 weeks) or itraconazole (3 pulses, 400 mg/day for 7 days) + K101 nail solution daily, or K101 nail solution monotherapy. Efficacy outcomes at 12 and 15 months were analyzed.

Results

At 12 months, the clinical cure rate for combination of terbinafine + K101 solution was significantly higher than that for K101 monotherapy (p = 0.008). Patients receiving this combination also showed significant improvement in percent of affected nail at 3 months (p = 0.029), while patients receiving itraconazole + K101 solution demonstrated improvement in percent of affected nail at 6 months (p = 0.037). At 15 months, there was no significant difference between treatments for complete, clinical, and mycological cure.

Conclusion

Combination therapy with oral terbinafine or itraconazole and K101 nail solution results in clearance of infected nail earlier than that with topical K101 alone. These combinations may encourage compliance and be effective for patients with moderate onychomycosis.

Efficacy and tolerability of amorolfine 5% nail lacquer in combination with systemic antifungal agents for onychomycosis: A meta-analysis and systematic review

The efficacy and safety of amorolfine 5% nail lacquer in combination with systemic antifungal agents in the treatment of the onychomycosis were evaluated. According to our meta-analysis, combination treatment of amorolfine 5% nail lacquer and systemic antifungals can result in higher percentage of complete clearance of onychomycosis. It showed that the experimental combination group was more effective than monotherapy of the systemic antifungals [OR (odds ratio) = 1.97, 95%CI (95% confidence interval) = 1.44-2.69], and no more adverse events happened with the addition of amorolfine 5% nail lacquer (OR = .96, 95%CI = .56-1.63, p = .95). This effect strengthens the fact that amorolfine 5% nail lacquer in combination with systemic antifungal agents was better than the monotherapy of systemic antifungals like itraconazole and terbinafine.

Efficacy and Safety of Terbinafine 500 mg Once Daily in Patients with Dermatophytosis

Introduction:

Dermatophytosis are the most common fungal infections globally. Terbinafine is considered to have good potency against dermatophytes, but resistance to terbinafine is on the rise.

Objective:

The objective of this study was to evaluate the efficacy and safety of terbinafine 500 mg given once daily in treatment of patients with superficial dermatophytosis.

Materials and Methods:

It was a retrospective questionnaire-based survey. Each doctor was given survey questionnaire booklet containing survey forms. Clinical response was graded according to the improvement in the affected lesion. Mycological cure was defined as negative microscopy under potassium hydroxide examination and a negative culture in Sabouraud's dextrose agar. Patients were divided into three groups depending on the duration of therapy, Group A – terbinafine 500 mg for 2 weeks, Group B – terbinafine 500 mg for 4 weeks, and Group C – terbinafine 500 mg for 6 weeks.

Results:

Total 50 doctors completed the survey involving 440 patients. In Group A, out of 194 patients, 87% (n = 169) patients showed very good response. In Group B, out of 211 patients, 92% (n = 194) of the patients showed very good response with >75% improvement in their lesion. In Group C, out of 35 patients, 80% (n = 30) patients showed very good response. Adverse drug reactions of mild to moderate intensity related to terbinafine were seen in 57 patients.

Conclusion:

Our survey indicates that terbinafine in a dose of 500 mg given once daily was efficacious and safe in the treatment of patients with dermatophytosis.

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.

Fusarium onychomycosis: prevalence, clinical presentations, response to itraconazole and terbinafine pulse therapy, and 1-year follow-up in nine cases

BACKGROUND

Invasive fusariosis is an infection with Fusarium spp. that primarily affects patients with hematologic malignancies and hematopoietic cell transplant recipients. Wounds, digital ulcers, onychomycosis, and paronychia are the typical cutaneous portals of entry. Early management of mycotic nails in immunocompromised and diabetic hosts is crucial to prevent life-threatening disease.

OBJECTIVES

We report nine cases of Fusarium onychomycosis (F. dimerum, n = 5; F. oxysporum, n = 3; Fusarium spp., n = 1) in immunocompetent hosts and their response to itraconazole and terbinafine pulse therapy.

METHODS

The patients received either itraconazole 400 mg daily or terbinafine 500 mg daily for 7 d/month; two pulses for fingernails and three pulses for toenails.

RESULTS

Of the 68 confirmed cases of onychomycosis, eight (11.7%) were Fusarium spp.; the ninth patient was culture positive but microscopy negative and responded well to itraconazole. Distal subungual onychomycosis was the commonest clinical manifestation (seven of nine), one had proximal subungual onychomycosis, and total onychodystrophy was noted on four patients. Associated paronychia was marked on 66.7% (six of eight) patients. Itraconazole was given to six patients/25 nails and terbinafine to three patients/20 nails. All nine patients completed treatments, but one defaulted at 12 months follow-up. The efficacy parameters were clinical cure (CC) and mycological cure (MC). At month 12 after the start of treatment, the response was itraconazole CC 13 of 25 (52%)/MC four of six (66.6%) and terbinafine CC four of eight (50%)/MC one of two (50%). Recurrence was noted in four of 13 (30.7%) and eight of 13 (61.5%) cured nails in the itraconazole group within 3 and 12 months, respectively.

CONCLUSIONS

Fusarium onychomycosis was clinically indistinguishable from other onychomycosis. Both itraconazole and terbinafine pulse therapy were only partially effective on Fusarium onychomycosis. Antifungals that are more effective should be sought.

Management of Onychomycosis in Canada in 2014

Background

Onychomycosis has several clinical presentations and is caused by various infectious organisms.

Objective

To provide guidance for selection of appropriate treatment.

Methods

The literature on onychomycosis management was reviewed to generate an evidence-based decision tree.

Results and Conclusion

Several options are available: terbinafine, itraconazole, fluconazole, ciclopirox 8% nail lacquer, efinaconazole 10% nail solution, and laser therapy. Further studies on lasers are needed before use can be recommended. Nondermatophyte molds or mixed infection can be managed with terbinafine or itraconazole with or without topicals. Itraconazole, fluconazole, and efinaconazole can be used for Candida infection. For dermatophytes, topicals can be considered for mild to moderate onychomycosis. For moderate to severe cases, any oral monotherapy can be used; however, we suggest terbinafine if there is a possibility of a drug interaction. These recommendations can be applied for all ages, immune function, or metabolic status, but proper monitoring and contraindications should be taken into consideration.

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.

Transungual delivery: deliberations and creeds

Although considered as trifling illness, nail diseases have a reasonably high occurrence and a noteworthy impact on the patients' quality of life. Furthermore, there is a need to improve the topical treatment for nail diseases to avoid drug interactions and to reduce side effects associated with oral therapy. Topical drug delivery to the nails has established amplified consideration lately. Strategies (such as chemical enhancers, formulation strategies, physical and mechanical methods) are being investigated in order to improve drug permeability across the nail plate. The rationale of this review is to present contemporary information on the structure of human nail along with its comparison with animal hooves. Precincts of nail permeability have been briefly discussed with respect to factors like permeant's molecular size, hydrophilicity, charge and the nature of the vehicle. These factors affect drug uptake and permeation through the nail. Formulations like nail lacquers which mimic cosmetic varnish and colloidal carriers along with nail substitutes that can be utilized for transungual delivery have also been discussed.

The human nail--barrier characterisation and permeation enhancement

The human nail remains one of the most challenging membranes for formulation scientists to target and for clinicians to heal. Its formidable barrier properties are the primary reason that oral therapy remains the primary approach to manage ungual infections. This article considers the major structural properties underlying the excellent barrier function of the nail, with particular emphasis on the role of biophysical methods in advancing our knowledge of this appendage. Formulations currently available for management of ungual disease are discussed and their therapeutic efficacy is assessed. Finally, experimental strategies to enhance ungual permeation are reviewed and prospects for future developments in the field are considered.

Antifungal susceptibility of dermatophytes isolated from patients with chronic renal failure

BACKGROUND

The prevalence of dermatophytosis in the general population is high, particularly in patients with chronic renal failure. Treatment requires the use of topical and/or systemic antifungal drugs. The efficacy of antifungal agents for the treatment of dermatophytosis has yet to be evaluated. Studies evaluating the in vitro activity of antifungal agents are rare, particularly in filamentous fungi.

OBJECTIVE

To evaluate the susceptibility profile of different species of dermatophytes isolated from patients with chronic renal failure to nine antifungal drugs available on the market for the treatment of dermatophytosis.

METHODS

Twenty-six isolates of dermatophytes obtained from patients with chronic renal failure were analyzed with respect to their susceptibility to nine antifungal agents (ketoconazole, ciclopirox olamine, fluconazole, griseofulvin, itraconazole, miconazole, piroctone olamine, terbinafine and tioconazole), using the broth microdilution method proposed by the Clinical and Laboratory Standards Institute (CLSI) and adapted for dermatophytes.

RESULTS

Of the antifungal agents tested, the best results in terms of sensitivity were found with terbinafine and tioconazole, while the antifungal activity of fluconazole was found to be weak, particularly against strains of M. gypseum. Ciclopirox olamine, although less effective than terbinafine, also yielded satisfactory results.

CONCLUSIONS

In general, the sensitivity profile of the antifungal agents tested in this study was similar to results obtained in previous studies, confirming the need to determine which species is causing the dermatophytosis given that antifungal susceptibility varies from one species to another. Furthermore, the present findings show the importance of conducting in vitro sensitivity tests, since the sensitivity profile may differ among isolates of the same species.

Efficacy, safety and tolerability of topical terbinafine nail solution in patients with mild-to-moderate toenail onychomycosis: results from three randomized studies using double-blind vehicle-controlled and open-label active-controlled designs

BACKGROUND

Terbinafine nail solution (TNS) was developed for the treatment of onychomycosis.

OBJECTIVE

To assess the efficacy of TNS vs. vehicle and amorolfine 5% nail lacquer.

METHODS

Subjects with mild-to-moderate toe onychomycosis (25% to ≤75% nail-involvement, matrix uninvolved) were randomized to receive either TNS or vehicle in two double-blind studies, and to TNS or amorolfine in an active-controlled, open-label study. Primary endpoint was complete cure (no residual clinical involvement and negative mycology) at week 52. Secondary endpoints were mycological cure (negative mycology defined as negative KOH microscopy and negative culture) and clinical effectiveness (≤10% residual-involvement and negative mycology) at week 52.

RESULTS

Complete cure was not different between TNS vs. vehicle and amorolfine. Mycological cure was higher with TNS vs. vehicle, as was clinical effectiveness with TNS vs. vehicle, and TNS and amorolfine were not different for secondary efficacy endpoints. Patients achieving mycological cure had a better clinical outcome, and efficacy was improved in subjects with milder disease. Post hoc analysis suggests that nail thickness is an important prognostic factor. Moreover, mycological cure may require 6 months of treatment regimen while complete cure and clinical effectiveness may be achievable only after 10 months. A simulation study suggests that longer treatment duration would have resulted in higher complete cure with TNS vs. vehicle. Study treatments were well-tolerated.

CONCLUSION

Primary efficacy objectives were not met in the studies reported herein. Possible reasons for failure to achieve significant outcomes include insufficient length of treatment; stringency of primary endpoint and severity of nail involvement of study population.

Recent updates in oral terbinafine: its use in onychomycosis and tinea capitis in the US

Onychomycosis and tinea capitis are prevalent fungal diseases that are difficult to cure and usually require systemic treatment. Onychomycosis has high recurrence rates and can significantly affect a patient's quality of life. Oral terbinafine has been approved for onychomycosis for 20 years in Europe and 15 years in the United States. Over these past 20 years, numerous studies show that oral terbinafine is a safe and efficacious treatment for onychomycosis. More recently, oral terbinafine also has been approved for tinea capitis. Once difficult to treat, terbinafine has revolutionised treatment of these fungal diseases. It has minimal side effects and its limited drug interactions make it an excellent treatment option for patients with co-morbidities. This review discusses oral terbinafine and new insights into the treatment of onychomycosis and tinea capitis. Recent publications have enhanced our knowledge of the mechanisms of oral terbinafine and its efficacy in treating onychomycosis. Oral terbinafine vs. other antifungal therapeutic options are reviewed. Overall, terbinafine remains a superior treatment for dermatophyte infections because of its safety, fungicidal profile, once daily dosing, and its ability to penetrate the stratum corneum.

Activity of TDT 067 (terbinafine in Transfersome) against agents of onychomycosis, as determined by minimum inhibitory and fungicidal concentrations

TDT 067 is a novel carrier-based dosage form (liquid spray) of 15 mg/ml of terbinafine in Transfersome that has been developed to deliver terbinafine to the nail bed to treat onychomycosis. In this study, we report the in vitro activities of TDT 067 against dermatophytes, compared with those of the Transfersome vehicle, naked terbinafine, and commercially available terbinafine (1%) spray. The MICs of TDT 067 and comparators against 25 clinical strains each of Trichophyton rubrum, T. mentagrophytes, and Epidermophyton floccosum were determined according to the CLSI M38-A2 susceptibility method (2008). Minimum fungicidal concentrations (MFCs) were determined by subculturing visibly clear wells from the MIC microtiter plates. TDT 067 demonstrated potent activity against the dermatophyte strains tested, with an MIC range of 0.00003 to 0.015 μg/ml. Overall, TDT 067 MIC(50) values (defined as the lowest concentrations to inhibit 50% of the strains tested) were 8-fold and 60-fold lower than those of naked terbinafine and terbinafine spray, respectively. The Transfersome vehicle showed minimal inhibitory activity. TDT 067 demonstrated lower MFC values for T. rubrum and E. floccosum than naked terbinafine and terbinafine spray. TDT 067 has more potent antifungal activity against dermatophytes that cause nail infection than conventional terbinafine preparations. The Transfersome vehicle appears to potentiate the antifungal activity of terbinafine. Clinical investigation of TDT 067 for the topical treatment of onychomycosis is warranted.

[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.

Update on terbinafine with a focus on dermatophytoses

Since terbinafine was introduced on the world market 17 years ago, it has become the leading antifungal for the treatment of superficial fungal infections, aided by unique pharmacologic and microbiologic profiles. This article reviews mode of action, antimycotic spectrum and disposition profile of terbinafine. It examines the data, accumulated over 15 years, on the comparative efficacy of terbinafine (vs griseofulvin, itraconazole, fluconazole) in the management of the infections for which it is primarily indicated (eg, dermatophytoses) and provides a brief discussion on its use for the treatment of non-dermatophyte infections. Finally, the available data on the newest topical and systemic formulations are introduced.

Current management of onychomycosis

Onychomycosis is the most common single cause of nail dystrophy and has a marked impact on quality of life. The availability of newer topical and systemic antifungal agents has improved our ability to effectively treat this condition. This article will review the most commonly used therapies and discuss the relative advantages and disadvantages of different treatment strategies.