New approaches to the treatment of onychomycosis

Preparation and valuation of a topical solution containing eutectic mixture of itraconazole and phenol

The purposes of this study were to prepare a topical solution containing itraconazole (ITR)-phenol eutectic mixture and to evaluate its ex vivo skin permeation, in vivo deposition and in vivo irritation. The eutectic mixture was prepared by agitating ITR and phenol (at a weight ratio of 1:1) together at room temperature. The effects of additives on the skin permeation of ITR were evaluated using excised hairless mouse skin. The in vivo skin deposition and skin irritation studies were performed in Sprague-Dawley rat and New Zealand white rabbit model. The permeability coefficient of ITR increased with addition of oleic acid in the topical solution. Otherwise, the permeability coefficient was inversely proportional to the concentration of the thickening agent, HPMC. The optimized topical solution contained 9 wt% of the ITR-phenol eutectic mixture, 9.0 wt% of oleic acid, 5.4 wt% of hydroxypropylmethyl cellulose and 76.6 wt% of benzyl alcohol. The steady-state flux and permeability coefficient of the optimized topical solution were 0.90 ± 0.20 μg/cm(2)·h and 22.73 ± 5.73 × 10(6) cm/h, respectively. The accumulated of ITR in the epidermis and dermis at 12 h was 49.83 ± 9.02 μg/cm(2). The topical solution did not cause irritation to the skins of New Zealand white rabbits. Therefore, the findings of this study indicate the possibilities for the topical application of ITR via an external preparation.

Forty-eight-hour diagnosis of onychomycosis with subtyping of Trichophyton rubrum strains

A novel strategy for the molecular identification of fungal agents of onychomycosis (including Trichophyton rubrum) has been designed based on the use of species-specific and universal primers in conjunction with a commercial kit that allows the extraction of DNA directly from the nail specimens. The microsatellite marker T1, which is based on a (GT)n repeat, was applied for the species-specific identification of Trichophyton rubrum. To evaluate how often Scopulariopsis spp. are detected in nail specimens, a second primer pair was designed to amplify specifically a 336-bp DNA fragment of the 28S region of the nuclear rRNA gene of S. brevicaulis and closely related species. Other fungal species were identified using amplification of the internal transcribed spacer (ITS) region of the rRNA gene, followed by restriction fragment length polymorphism analysis or sequencing. In addition, polyacrylamide gel separation of the T1-PCR product allowed subtyping of T. rubrum strains. We studied 195 nail specimens (the "nail sample") and 66 previously collected etiologic strains (the "strain sample") from 261 onychomycosis patients from Bulgaria and Greece. Of the etiologic agents obtained from both samples, T. rubrum was the most common organism, confirmed to be present in 76% of all cases and serving as the sole or (rarely) mixed etiologic agent in 199 of 218 cases (91%) where the identity of the causal organism(s) was confirmed. Other agents seen included molds (6% of cases with identified etiologic agents; mainly S. brevicaulis) and other dermatophyte species (4%; most frequently Trichophyton interdigitale). Simultaneous infections with two fungal species were confirmed in a small percentage of cases (below 1%). The proportion of morphologically identified cultures revealed by molecular study to have been misidentified was 6%. Subtyping revealed that all but five T. rubrum isolates were of the common type B that is prevalent in Europe. In comparison to microscopy and culture, the molecular approach was superior. The PCR was more sensitive (84%) than culture (22%) in the nail sample and was more frequently correct in specifically identifying etiologic agents (100%) than microscopy plus routine culture in either the nail or the strain samples (correct culture identifications in 96% and 94% of cases, respectively). Using the molecular approach, the time for diagnosing the identity of fungi causing onychomycosis could be reduced to 48 h, whereas culture techniques generally require 2 to 4 weeks. The early detection and identification of the infecting species in nails will facilitate prompt and appropriate treatment and may be an aid for the development of new antifungal agents.

Pulse versus continuous terbinafine for onychomycosis: A randomized, double-blind, controlled trial

BACKGROUND

Effective treatments for onychomycosis are expensive. Previous studies suggest that less costly, pulsed doses of antifungal medications may be as effective as standard, continuous doses. Terbinafine is the current treatment of choice for toenail onychomycosis.

OBJECTIVE

Our purpose was to determine whether pulse-dose terbinafine is as effective as standard continuous-dose terbinafine for treatment of toenail onychomycosis.

METHODS

We conducted a double-blind, randomized, noninferiority, clinical intervention trial in the Minneapolis Veterans Affairs Medical Center. The main inclusion criteria for participants were a positive dermatophyte culture and at least 25% distal subungual clinical involvement. Six hundred eighteen volunteers were screened; 306 were randomized. Terbinafine, 250 mg daily for 3 months (continuous) or terbinafine, 500 mg daily for 1 week per month for 3 months (pulse) was administered. The primary outcome measure was mycological cure of the target toenail at 18 months. Secondary outcome measures included clinical cure and complete (clinical plus mycological) cure of the target toenail and complete cure of all 10 toenails.

RESULTS

Results of an intent-to-treat analysis did not meet the prespecified criterion for noninferiority but did demonstrate the superiority of continuous-dose terbinafine for: mycological cure of the target toenail (70.9% [105/148] vs 58.7% [84/143]; P =.03, relative risk [RR] of 1.21 [95% confidence interval (CI), 1.02-1.43]); clinical cure of the target toenail (44.6% [66/148] vs 29.3% [42/143]; P =.007, RR =1.52 [95% CI, 1.11-2.07); complete cure of the target toenail (40.5% [60/148] vs 28.0% [40/143]; P =.02, RR=1.45 [95% CI, 1.04-2.01); and complete cure of all 10 toenails (25.2% [36/143] vs 14.7% [21/143]; P =.03, RR =1.71 [95% CI, 1.05-2.79). Tolerability of the regimens did not differ significantly between the groups (chi2 =1.63; P =.65).

LIMITATIONS

The study population primarily consisted of older men with severe onychomycosis.

CONCLUSIONS

This study demonstrated the superiority of continuous- over pulse-dose terbinafine. We also found this expensive therapy to be much less effective than previously believed, particularly for achieving complete cure of all 10 toenails.

The systemic treatment of onychomycosis

The systemic treatment of fungal infections has changed considerably over the past 10 to 20 years. Though griseofulvin was introduced in the late 1950s and was at the time the only Food and Drug Administration (FDA)-approved drug in the United States for the systemic treatment of onychomycosis, its cure rate seldom exceeds 40%. Newer drugs appear to be reducing treatment times, improving cure rates with a minimum of side effects, and achieving long-term remissions in recalcitrant infections. Itraconazole was FDA approved in 1995, and terbinafine was FDA approved in 1996. Both have been used safely for many years, demonstrating efficacy in short-term treatment with a low incidence of side effects. Fluconazole, though not yet FDA approved for onychomycosis, has also shown efficacy in many situations. Direct-to-the-public advertising has raised interest in patients to seek treatment. There are also some new investigational drugs for fungal infections that may augment or supplant current therapy.

Itraconazole versus terbinafine in the management of onychomycosis: an overview

Ever since the introduction of itraconazole and terbinafine in the management of onychomycosis, there has been a revival of interest in the latter. In order to comprehend the intricate emerging scenario, an endeavor has been made to form a distinct outline in the shape of an overview on several of their facets. The review, therefore, envisages forming and facilitating instant decision-making.

Candida: a causative agent of an emerging infection

Incidences of infections due to Candida have increased over the last 15-20 y. This increase in the incidence and the high associated mortality rate despite therapy has focused the attention on this disease and prompted investigators to undertake research aimed at understanding the pathogenesis of this disease as well as methods to treat it. This paper discusses recent developments in the Candida field and the impact they have on patient management.

Intermittent pulse therapy with itraconazole for onychomycosis. Experience in Hong Kong Chinese

Forty-four Hong Kong Chinese adults comprising 10 cases of fingernail and 42 cases of toenail onychomycosis were recruited for a 3-weekly itraconazole pulse therapy. Each pulse consisted of seven consecutive daily 400 mg doses with a 3-week interval between treatments. All patients in the fingernail group and 37 in the toenail group completed the study. The clinical cure, clinical response and mycological cure rates at week 36 were 70, 90 and 90% for fingernail and 35, 81 and 68% for toenail groups, respectively. Side-effects including biochemical abnormalities were minimal, and returned to normal upon cessation of treatment. We conclude that itraconazole pulse therapy is very effective, safe and well-tolerated for fingernail and toenail onychomycosis.

Practice guidelines for the treatment of candidiasis. Infectious Diseases Society of America

Infections due to Candida species are the most common of the fungal infections. Candida species produce a broad range of infections, ranging from nonlife-threatening mucocutaneous illnesses to invasive process that may involve virtually any organ. Such a broad range of infections requires an equally broad range of diagnostic and therapeutic strategies. This document summarizes current knowledge about treatment of multiple forms of candidiasis and is the guideline of the Infectious Diseases Society of America (IDSA) for the treatment of candidiasis. Throughout this document, treatment recommendations are scored according to the standard scoring scheme used in other IDSA guidelines to illustrate the strength of the underlying data. The document covers 4 major topical areas. The role of the microbiology laboratory. To a greater extent than for other fungi, treatment of candidiasis can now be guided by in vitro susceptibility testing. The guidelines review the available information supporting current testing procedures and interpretive breakpoints and place these data into clinical context. Susceptibility testing is most helpful in dealing with infection due to non-albicans species of Candida. In this setting, especially if the patient has been treated previously with an azole antifungal agent, the possibility of microbiological resistance must be considered. Treatment of invasive candidiasis. In addition to acute hematogenous candidiasis, the guidelines review strategies for treatment of 15 other forms of invasive candidiasis. Extensive data from randomized trials are really available only for therapy of acute hematogenous candidiasis in the nonneutropenic adult. Choice of therapy for other forms of candidiasis is based on case series and anecdotal reports. In general, both amphotericin B and the azoles have a role to play in treatment. Choice of therapy is guided by weighing the greater activity of amphotericin B for some non-albicans species (e.g., Candida krusei) against the lesser toxicity and ease of administration of the azole antifungal agents. Flucytosine has activity against many isolates of Candida but is not often used. Treatment of mucocutaneous candidiasis. Therapy for mucosal infections is dominated by the azole antifungal agents. These drugs may be used topically or systemically and have been proven safe and efficacious. A significant problem with mucosal disease is the propensity for a small proportion of patients to suffer repeated relapses. In some situations, the explanation for such a relapse is obvious (e.g., relapsing oropharyngeal candidiasis in an individual with advanced and uncontrolled HIV infection), but in other patients the cause is cryptic (e.g., relapsing vaginitis in a healthy woman). Rational strategies for these situations are discussed in the guidelines and must consider the possibility of induction of resistance over time. Prevention of invasive candidiasis. Prophylactic strategies are useful if the risk of a target disease is sharply elevated in a readily identified group of patients. Selected patient groups undergoing therapy that produces prolonged neutropenia (e.g., some bone-marrow transplant recipients) or who receive a solid-organ transplant (e.g., some liver transplant recipients) have a sufficient risk of invasive candidiasis to warrant prophylaxis.

Onychomycosis in Icelandic swimmers

We investigated visitors to a swimming pool in Reykjavik to determine whether onychomycosis of the toenails is more prevalent in swimmers than in the general population, where the prevalence is believed to be between 3 and 8%. A total of 266 swimmers over the age of 17 years were interviewed and examined. When an onychomycosis was suspected a nail specimen was taken for mycological examination. Onychomycosis was clinically suspected in 105 cases (40%). In 60 cases (23%) a dermatophyte infection was confirmed by culture and 14 cases (5%) were microscopy-positive only. The prevalence of culture-positive onychomycosis was 15% in women and 26% in men. Our results suggest that onychomycosis of the toenails is at least 3 times more prevalent in swimmers than in the rest of the population.

Current and emerging azole antifungal agents

Major developments in research into the azole class of antifungal agents during the 1990s have provided expanded options for the treatment of many opportunistic and endemic fungal infections. Fluconazole and itraconazole have proved to be safer than both amphotericin B and ketoconazole. Despite these advances, serious fungal infections remain difficult to treat, and resistance to the available drugs is emerging. This review describes present and future uses of the currently available azole antifungal agents in the treatment of systemic and superficial fungal infections and provides a brief overview of the current status of in vitro susceptibility testing and the growing problem of clinical resistance to the azoles. Use of the currently available azoles in combination with other antifungal agents with different mechanisms of action is likely to provide enhanced efficacy. Detailed information on some of the second-generation triazoles being developed to provide extended coverage of opportunistic, endemic, and emerging fungal pathogens, as well as those in which resistance to older agents is becoming problematic, is provided.

Detection and differentiation of causative fungi of onychomycosis using PCR amplification and restriction enzyme analysis

BACKGROUND

Onychomycosis, a fungal nail infection, has become one of the most important dermatophytoses. Unfortunately, a predictably successful diagnostic approach to onychomycosis does not yet exist.

OBJECTIVE

The purpose of this study was to develop a deoxyribonucleic acid (DNA)-based diagnostic method to improve the sensitivity and specificity of the detection and differentiation of the pathogenic fungi of onychomycosis.

METHODS

We attempted to detect fungi in the nail using polymerase chain reaction (PCR) primer systems that were designed in conserved sequences of the small ribosomal subunit 18S-rRNA genes shared by most fungi, and differentiated between species by restriction enzyme analysis of the amplified product.

RESULTS

Fragments of the gene coding for 18S-rRNA were amplified successfully from medically important fungi species, but not from normal nails. Restriction fragment length polymorphism patterns using HaeIII endonuclease were sufficiently different to allow the recognition of individual species.

CONCLUSIONS

The PCR-restriction enzyme analysis method appears to be a more sensitive detection and identification technique for onychomycosis than conventional methods, and has considerable diagnostic value.

Onychomycosis: pathogenesis, diagnosis, and management

Although not life-threatening, onychomycosis (a fungal infection of the nail, usually caused by a dermatophyte) constitutes an important public health problem because of its high prevalence (about 10% of the U.S. population) and associated morbidity. The disease can have certain negative consequences for patients, such as pain, and can potentially undermine work and social lives. This review discusses the etiology, classification, diagnosis, and treatment of onychomycosis. Four types of onychomycosis are recognized based on the site and pattern of fungal invasion. Dermatophyte fungi are the predominant pathogens, but yeasts (especially Candida albicans) and nondermatophyte molds may also be implicated. Accurate diagnosis requires direct microscopy and fungal culture. The differential diagnosis includes psoriasis, lichen planus, onychogryphosis, and nail trauma. Onychomycosis is more difficult to treat than most dermatophytoses because of the inherent slow growth of the nail. Older antifungal agents (ketoconazole and griseofulvin) are unsuitable for onychomycosis because of their relatively poor efficacy and potential adverse effects. Three recently developed antimycotic agents (fluconazole, itraconazole, and terbinafine) offer high cure rates and good safety profiles. In addition, the short treatment times (< 3 months) and intermittent dosing schedules are likely to enhance compliance and reduce the costs of therapy.

Pharmacokinetics and pharmacology of terbinafine and itraconazole

BACKGROUND

Two new systemic antifungal agents, terbinafine and itraconazole, have expanded the choices for treatment of onychomycosis. The pharmacokinetic and pharmacologic properties provide the basis of their activity and are related to their efficacy and safety in dermatophyte infections.

OBJECTIVE

We describe the pharmacodynamics, pharmacokinetics, and pharmacology of terbinafine and itraconazole and the features that form a framework for comparing their efficacy. PHARMACODYNAMICS: Both terbinafine and itraconazole ultimately block ergosterol synthesis; terbinafine disrupts fungal cell wall synthesis earlier (squalene to squalene epoxide) than does itraconazole (lanosterol to ergosterol). In vitro, terbinafine exposure results in a toxic accumulation of squalene and decreased production of ergosterol. Minimal inhibitory concentrations (MICs) of terbinafine for dermatophytes are essentially equal to minimal fungicidal concentrations (MFCs). However, the MFCs of itraconazole are much higher than the MICs. PHARMACOLOGIC PROFILE: Both itraconazole and terbinafine penetrate keratinizing tissue; levels reached in nail plate exceed those in plasma. Therapeutic levels of the itraconazole persist in nails for up to 6 months after discontinuation of 3 months of therapy (200 mg/day) and during various pulsed cycles. After discontinuation of 1 month of therapy, terbinafine persists at therapeutic levels in the nail. Itraconazole has an affinity for mammalian cytochrome P-450 enzymes as well as for fungal P-450-dependent enzyme, and thus has the potential for clinically important interactions (e.g., astemizole, terfenadine, rifampin, oral contraceptives, H2 receptor antagonists, warfarin, cyclosporine). Terbinafine is not metabolized through this system and has little potential for drug-drug interactions.

CONCLUSION

The low MFCs exhibited by terbinafine for dermatophytes may be important in its clinical efficacy and low relapse rates. The safety profile of terbinafine directly reflects its mechanism of action.

Twelve weeks of continuous oral therapy for toenail onychomycosis caused by dermatophytes: a double-blind comparative trial of terbinafine 250 mg/day versus itraconazole 200 mg/day

BACKGROUND

Dermatophyte infections of the toenail have been difficult to treat, requiring long courses of therapy and having high recurrence rates. New oral antifungal agents with better outcomes and minimal adverse events are needed.

OBJECTIVE

The purpose of this study was to compare two newer antifungal compounds, terbinafine and itraconazole, for efficacy and safety in toenail onychomycosis caused by dermatophytes.

METHODS

The study was randomized and double-blind. It compared 12 weeks of continuous oral treatment with terbinafine 250 mg/day or itraconazole 200 mg/day for confirmed toenail dermatophyte onychomycosis. Clinical symptoms and mycologic outcome were assessed at weeks 4, 8, 12, 24, 36, and 48. A total of 372 patients (186 in each group) with dermatophyte infection confirmed by microscopy and culture were included in the intent-to-treat analysis.

RESULTS

At week 48, a statistically significantly greater percentage of the terbinafine group than itraconazole group showed negative mycology (73% [119 of 163] vs 45.8% [77 of 168]; p < 0.0001) (difference = 27.2%; 95% CI = [17.0%, 37.3%]). The difference was also confirmed clinically (p = 0.001) in the patients who were clinically cured or had only minimal symptoms at the end of the study (76.2% [125 of 164] vs 58.1% [100 of 172]) (difference = 18.1%; 95% CI = [8.24%, 27.9%]). The geometric mean length of healthy nail of the big toe was significantly greater in the terbinafine than itraconazole group (8.1 vs 6.4 mm; p = 0.026). Tolerability was good to very good in almost 90% of patients in both groups, and all reported adverse events were known for these compounds.

CONCLUSION

Terbinafine produced higher rates of clinical and mycologic cure at follow-up than did itraconazole.

Superficial fungal infections. Errors to avoid in diagnosis and treatment

Superficial fungal infections are easily managed once the proper diagnosis is made. However, misdiagnosis is not uncommon, and many standard approaches to treatment popular just a few years ago are now out of date or in need of refinement. Through nine illustrative cases, the authors describe pitfalls in diagnosis and treatment of common fungal infections involving the skin, hair, and nails.

Itraconazole therapy is effective for pedal onychomycosis caused by some nondermatophyte molds and in mixed infection with dermatophytes and molds: a multicenter study with 36 patients

BACKGROUND

Onychomycosis of the toenail caused by nondermatophyte molds alone or in combination with dermatophytes is difficult to eradicate with standard antifungal therapy.

OBJECTIVE

Our purpose was to determine the effectiveness of itraconazole in the treatment of toenail onychomycosis caused by molds alone or in combination with dermatophytes.

METHODS

We treated 36 patients with this drug given as continuous dosing (100 or 200 mg/ day) for 6 to 20 weeks or as a 1-week pulse dosing (200 mg twice daily for 1 week per month) for two to four pulses.

RESULTS

Patients with toenail onychomycosis with the following organisms were treated: Aspergillus spp. (eight patients), Fusarium spp. (four patients), Scopulariopsis brevicaulis (23 patients), and Alternaria spp. (one patient). Nineteen patients had onychomycosis with a mixed origin. At follow-up, 12 months after therapy was initiated, clinical and mycologic cure was achieved in 15 of 17 patients (88%) with onychomycosis caused by a single mold. In patients with mixed infection, a clinical cure was obtained in 16 of 19 patients (84%) and a mycologic cure in 13 of 19 patients (68%).

CONCLUSION

Itraconazole appears to be effective and safe for the treatment of toenail onychomycosis caused by some nondermatophyte molds alone or in combination with dermatophytes.

Current management of onychomycosis. An overview

Until recently pedal onychomycosis, particularly when it affected several nails or involved a large nail plate area, was often regarded as untreatable. The advent of new therapies such as itraconazole, terbinafine, and fluconazole has been a significant and welcome addition to the armamentarium of therapies at the disposal of the physician. These drugs appear in the nail plate within days of starting oral therapy, being taken up by both the nail matrix and the nail bed. The duration required for effective therapy has been reduced, while the efficacy rates and cost-effectiveness have increased compared with the older treatments, such as griseofulvin. Some of the newer agents appear to have a wider spectrum of activity. Thus far, the newer agent have exhibited a low risk to benefit ratio. I may be possible to combine oral therapies with topical and surgical treatments, thereby further increasing efficacy rates and the cost-effectiveness while decreasing adverse effects and duration of oral therapy.

New therapies for onychomycosis

Until recently, the treatment of onychomycosis was discouraging because of the relatively low success rate, the need for prolonged therapy, and the laboratory monitoring necessary with the traditional oral antifungal agents, griseofulvin and ketoconazole. The advent of a new generation of oral antifungal drugs, including two triazoles (itraconazole and fluconazole) and an allylamine (terbinafine), has greatly improved the outlook for patients with fungal nail infections, particularly those with toenail involvement. Recently, the broad-spectrum triazole, itraconazole, has been approved for the treatment of onychomycosis in the U.S. Numerous studies have demonstrated its efficacy when administered either continuously for 3 months or in "pulse" dosing. Preliminary findings suggest that fluconazole and terbinafine are also promising, although their spectrum of activity is not as broad as that of itraconazole.

Pharmacoeconomic analysis of oral therapies for onychomycosis: a US model

An evaluation of treatment practices in 13 countries, not including the United States, has shown oral terbinafine to be more cost-effective (from a government payer perspective) than griseofulvin, itraconazole, and ketoconazole in the treatment of onychomycosis of toenails and fingernails. The purpose of this study was to evaluate the clinical and economic effects of oral griseofulvin, itraconazole, ketoconazole, and terbinafine in the treatment of onychomycosis from the perspective of a third-party payer in the United States. A previously constructed decision-analytic model evaluating the costs of onychomycosis in 13 countries outside the United States was updated to determine the costs of treating onychomycosis in the United States. Clinical management patterns were assessed to identify and quantify physician visits, laboratory tests, and adverse drug reaction treatment components for patients with toenail and fingernail onychomycosis. A random-effects model meta-analysis of treatment efficacy (mycologic cure) and New York Metropolitan Medicare charge data for physician fees were used in the treatment model. A sensitivity analysis assessing alternative dosing regimens and a rank order stability analysis investigating the effects of length of treatment, success rates, relapse rates, and drug acquisition costs on overall results were also conducted. Terbinafine had the lowest cost per mycologic cure after one treatment regimen for onychomycosis in both toenail and fingernail infections ($791.00 and $454.00, respectively). The costs of treating toenail and fingernail infections were comparatively higher for therapy with itraconazole ($1535.00 and $767.00, respectively), griseofulvin ($2385.00 and $837.00, respectively), and ketoconazole ($10,025.00 and $1512.00, respectively). As a primary treatment choice, terbinafine also had the lowest overall expected cost per patient for both toenail and fingernail infections ($977.00 and $550.00, respectively). Griseofulvin had expected costs ($1543.00 and $822.00, respectively) similar to itraconazole ($1588.00 and $894.00, respectively), whereas ketoconazole was the most expensive primary treatment choice ($2359.00 and $1287.00, respectively). This study demonstrates that terbinafine is an economical and cost-effective treatment for patients with dermatophytic onychomycosis, supporting European and Canadian studies. Except for the rank order of griseofulvin and itraconazole, sensitivity analyses show that these results are fairly stable.

Treatment of dermatophyte nail infections: an open randomized study comparing intermittent terbinafine therapy with continuous terbinafine treatment and intermittent itraconazole therapy

BACKGROUND

terbinafine persists in the nail at effective concentrations for several weeks after discontinuation of treatment.

OBJECTIVE

Our purpose was to verify whether intermittent terbinafine therapy is effective in dermatophytic onychomycosis and to compare the results of intermittent terbinafine with those of intermittent itraconazole and continuous terbinafine treatment.

METHODS

An open, randomized study of 63 patients was performed with three treatment regimens: terbinafine, 250 mg daily (21 patients); terbinafine, 500 mg daily for 1 week every month (21 patients); or itraconazole, 400 mg daily for 1 week every month (21 patients). Treatment was continued for 4 months in toenail infections (60 patients) and 2 months in fingernail infections (3 patients).

RESULTS

At the end of the follow-up period (6 months after discontinuation of treatment) 16 of the 17 patients (94.1%) with toenail onychomycosis were mycologically cured in the terbinafine 250 mg group, 16 of 20 (80%) in the terbinafine 500 mg group, and 15 of 20 (75%) in the itraconazole group.

CONCLUSION

The percentage of patients who were mycologically cured was higher in the continuous terbinafine group than in the intermittent terbinafine and itraconazole groups, but statistical analysis did not reveal any significant difference between these cure rates.

Recent developments in antifungal therapy

There have been many advances during the past few years relating to the treatment of superficial fungal infections. This article focuses on recent developments, particularly in oral therapy, but in topical therapy as well. First, the newer agents (especially fluconazole, itraconazole, and terbinafine) are reviewed, and then the use of these agents in many disorders is discussed, with emphasis on tinea corporis or cruris, tinea pedis, tinea capitis, and onychomycosis.

Results of German multicenter study of antimicrobial susceptibilities of Trichophyton rubrum and Trichophyton mentagrophytes strains causing tinea unguium. German Collaborative Dermatophyte Drug Susceptibility Study Group

Thirty-two strains of Trichophyton rubrum and 16 strains of Trichophyton mentagrophytes isolated from patients with tinea unguium in various parts of Germany were subjected to a microdilution test with six systemic or topical antimycotic agents. Apart from griseofulvin, there were no species-specific differences between the two species. Terbinafine was the most active antimycotic agent, with a MIC not exceeding 0.05 micrograms/ml.

Oral therapeutic agents in fungal nail disease

Oral griseofulvin has been the first-line drug in the therapy of dermatophyte onychomycosis for many years. Even when used long-term, it is effective in only about 30% of patients. Ketoconazole is not much more effective than griseofulvin in toenail infections, and there are significant problems with hepatotoxicity. Recently the triazoles, itraconazole and fluconazole, and the allylamine, terbinafine, were introduced and are believed to be potentially suitable for the oral treatment of fungal nail infection. Terbinafine is particularly effective in the treatment of dermatophyte onychomycosis, with a much shorter treatment period than griseofulvin. Cure rates of well over 80% have been noted in fingernail and toenail infection during treatment periods of 6 and 12 weeks, respectively. Itraconazole, 200 mg/day, has been noted in some studies to be similarly effective in the same treatment period. Few studies of fluconazole in nail infection have been carried out. These new agents appear to be safe, and results thus far suggest that they will soon overtake griseofulvin as the drug of choice in the oral therapy of nail infection.

Acquired nail beading in patients receiving itraconazole--an indicator of faster nail growth? A study using optical profilometry

Nail surfaces of toe-nail fragments were analysed by optical profilometry in patients treated with two different dosages of itraconazole: 200 mg continuous dosing for 12 weeks, or a pulse-dose regimen of 1 week per month of 400 mg itraconazole daily for 3-4 months. The use of the latter regimen seemed clinically to increase nail growth, which was accompanied in several patients by the occurrence of nail surface irregularities. This aspect was studied by computerized optical profilometry. Nail beading was characterized by a higher number of peaks and a larger mean roughness value (Ra). Such findings are reminiscent of other nail alterations resulting from a faster matrix turnover. A substantially greater number of peaks and larger Ra were found in the patients receiving the pulse treatment than in those receiving the continuous-dose regimen. Pulse therapy with itraconazole therefore appears to modify the structure of the nail plate, probably as a result of, or in association with, an increased rate of growth.

Treatment of onychomycosis: traditional approaches

Fungal infections account for approximately 20% of all nail diseases, and the incidence of onychomycosis is increasing. Traditional therapies are often ineffective. The activity, clinical efficacy, pharmacokinetics, and patient acceptability of griseofulvin and ketoconazole, the two "traditional" oral agents, are reviewed and compared with two new agents, terbinafine and itraconazole. Both griseofulvin and ketoconazole are effective in dermatophyte infections but require long-term therapy. Ketoconazole, although also active against Candida species, is restricted in use by a rare incidence of hepatotoxicity. Terbinafine and itraconazole diffuse more rapidly into the stratum corneum and nail and are more effective with short-term treatment.