A pilot evaluation of pulse itraconazole vs. terbinafine for treatment of Candida toenail onychomycosis*

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.

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.

Oral therapy for onychomycosis: an evidence-based review

INTRODUCTION

Onychomycosis is a very common fungal infection of the nail apparatus; however, it is very hard to treat, even when the causative agent is identified, and usually requires prolonged systemic antifungal therapy. Until the 1990s, oral treatment options included only griseofulvin and ketoconazole, and the cure rate was very low. New generations of antimycotics, such as fluconazole, itraconazole and terbinafine have improved treatment success.

METHODS

Literature was identified by performing a PubMed Ovid MEDLINE, Ovid EMBASE, EBSCO CINAHL, and Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) search. Prospective and randomized clinical trials were chosen to be included in this review. Forty-six trials were included.

RESULTS

Fluconazole, itraconazole and terbinafine are effective in the treatment of onychomycosis and have a good safety profile. When a dermatophyte is the pathogen, terbinafine produces the best results. For Candida and nondermatophyte infections, the azoles, mainly itraconazole, are the recommended therapy.

CONCLUSION

In the majority of the studies, terbinafine treatment showed a higher cure ratio than the other drugs for dermatophyte onychomycosis.

Candidal onychomycosis: a mini-review

Onychomycosis is a common fungal infection affecting nails. The primary cause for onychomycosis is dermatophytes, while Candida species have emerged as second-line pathogens. Onychomycosis due to Candida (candidal onychomycosis) is increasingly found in individuals having defective immunity consequential to aging, diabetes mellitus, vascular diseases, HIV infection and drug therapies such as immunosuppressives and broad-spectrum antibiotics. Breached local immunity at the nail complex due to trauma, chronic exposure to moisture and chemicals including smoke, detergents, soap, etc., also contribute to candidal onychomycosis. Adhesion, filamentation, secretion of extracellular enzymes and the development of antifungal resistance are some of the virulence mechanisms of Candida species associated with onychomycosis. Diagnosis of onychomycosis depends on history and clinical examination, direct microscopic investigation, mycological culture and histopathology. Restoration of immune defenses, elimination of fungi using appropriate drug therapy and improvement of nail hygiene with the removal of predisposing factors are key aspects in the management of candidal onychomycosis.

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.

The significance of itraconazole for treatment of fungal infections of skin, nails and mucous membranes

Itraconazole is an antifungal drug from the triazole group with distinct in vitro activity against dermatophytes, yeasts and some molds. Itraconazole has a primarily fungistatic activity. Itraconazole accumulates in the stratum corneum and in nail material due to its high affinity to keratin, as well as in sebum and vaginal mucosa. Together with terbinafine and fluconazole, itraconazole belongs to the modern highly effective systemic antifungal drugs with a favorable risk-benefit ratio and for this reason is a preferred therapy option for fungal infections of skin, nails and mucous membranes. Compared to terbinafine in the treatment of fingernail and toenail fungal infections, itraconazole offers the advantage of a broad antifungal spectrum and better effectiveness against onychomycosis caused by yeasts yet appears inferior with regard to the more common dermatophyte infections. Itraconazole constitutes an important therapy option, along with fluconazole, terbinafine, ketoconazole and griseofulvin, for the treatment of dermatophyte infections of glabrous skin (tinea pedis, tinea manuum, tinea corporis and tinea cruris) in adults following unsuccessful topical therapy. In the oral therapy of tinea capitis, itraconazole plays an especially important role, in particular for disease caused by Microsporum canis (for children, however, only off-label use is feasible currently). In the treatment of oropharyngeal candidiasis, candidiasis of the skin and vulvovaginal candidiasis, itraconazole and fluconazole are the preferred treatment options in cases in which topical therapy has proven unsuccessful.

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.