Common Fungal Infections of the Feet in Patients with Diabetes Mellitus

Onychomycosis in Older Adults: Prevalence, Diagnosis, and Management

The risk of having onychomycosis increases with age. Data suggest that the prevalence of onychomycosis may be ≥ 20% in subjects aged ≥ 60 years and ≥ 50% in those aged ≥ 70 years. Older males are 2.1 times more prone to onychomycosis than are females. Although most nail dystrophies (approximately 50%) are caused by onychomycosis, proper clinical assessment followed by mycological examination is recommended to exclude other conditions such as nail trauma, lichen planus, and psoriasis. The US FDA-approved onychomycosis treatments are systemic antifungals (terbinafine and itraconazole) for severe onychomycosis and topical antifungals (ciclopirox 8%, efinaconazole 10%, and tavaborole 5%) for mild-to-moderate onychomycosis. Oral fluconazole is used off-label, and itraconazole may be considered for non-dermatophyte onychomycosis. Recently, fosravuconazole was approved in Japan for onychomycosis treatment. Although the treatment options and durations are the same for older patients as for other age groups, a clinical decision should take into account various age-related factors such as comorbidities, polypharmacy, hepatic and renal insufficiency, and noncompliance. Clinicians should also consider possible drug interactions and side effects when choosing a particular antifungal. Since the recurrence rate of onychomycosis is high, older patients should practice sanitization techniques, consider lifestyle changes, and perhaps consider using a topical antifungal as long-term maintenance therapy one to three times per week to prevent the recurrence of onychomycosis or to treat early disease.

Clinical evidences of urea at medium concentration

Urea-based topical compounds at medium concentrations (15%-30%) represent useful dermatological agents for their humectant and keratolytic effects by enhancing stratum corneum hydration and by loosening epidermal keratin, respectively. The aim of this paper is to review the clinical evidences of the use of 15%-30% urea as single topical agent. Although limited evidence supports the use of these concentrations of urea in skin disorders characterised by xerosis and hyperkeratosis, in clinical practice they are largely used especially in xerosis of limited skin areas, in which the side effects are tolerable, or hyperkeratosis involving large or more sensitive (eg, face, genital region, etc) areas, in which higher concentration may be irritant. In addition, urea at medium concentrations is used in combination with other substances including topical antifungals as penetration enhancer.

Physicochemical and pathohistological changes in experimental fibrosarcoma tumors of hamsters treated with metformin and itraconazole

The anticancer effects of metformin (an antihyperglycaemic agent) and itraconazole (an antifungal agent), which are established non-oncologic drugs, were investigated in the present study. The weight, diameter, volume, density, surface, surface to volume ratio and immunohistochemistry of experimental fibrosarcoma tumors were investigated in hamsters treated with metformin and itraconazole. Briefly, the hamsters were injected with BHK-21/C13 cells in order to induce fibrosarcoma, and the animals were treated daily with metformin, itraconazole or a combination of the two drugs. Subsequently, blood samples were obtained for biochemical analyses and the tumors were excised, weighed and measured. The tumor samples were pathohistologically and immunohistochemically assessed for proliferation marker protein Ki-67, hematopoietic progenitor cell antigen CD34, cytochrome c oxidase subunit 4 (COX4), glucose transporter 1 (GLUT1) and inducible nitric oxide synthase (iNOS), and vital organs were toxicologically tested. Ki-67-positivity and cytoplasmic marker (CD34, COX4, GLUT1, iNOS) immunoexpression in the tumor samples were quantified. The results revealed that the combination of metformin and itraconazole significantly altered the physicochemical and pathohistological characteristics of the hamster fibrosarcoma tumors, including absolute and relative weight, volume, density, length, surface area, surface to volume ratio, Ki-67-positivity and the immunoexpression of cytoplasmic markers, without indications of toxicity. Furthermore, metformin with itraconazole demonstrated antiproliferative functions in cervical carcinoma HeLa, colon carcinoma HT-29, lung carcinoma A549 and fibrosarcoma BHK-21/C13 cells, with markedly lower cytotoxicity in the normal fetal lung MRC-5 cells. In conclusion, the administration of metformin in combination with itraconazole may inhibit the growth of fibrosarcoma tumors in vivo and the proliferation of various malignant cell lines in vitro, suggesting that this may be an effective and safe approach as a nontoxic anticancer adjuvant and relapse prevention therapy.

A Practical Guide to Curing Onychomycosis: How to Maximize Cure at the Patient, Organism, Treatment, and Environmental Level

Onychomycosis is a fungal nail infection caused by dermatophytes, non-dermatophyte molds, and yeasts. Treatment of this infection can be difficult, with relapse likely to occur within 2.5 years of cure. The objective of this article is to review factors that can impact cure and to suggest practical techniques that physicians can use to maximize cure rates. Co-morbidities, as well as disease severity and duration, are among the many patient factors that could influence the efficacy of antifungal therapies. Furthermore, organism, treatment, and environmental factors that may hinder cure include point mutations, biofilms, affinity for non-target enzymes, and exposure to fungal reservoirs. To address patient-related factors, physicians are encouraged to conduct confirmatory testing and treat co-morbidities such as tinea pedis early and completely. To combat organism-focused factors, it is recommended that disruption of biofilms is considered, and drugs with multiple routes of delivery and unique mechanisms of action are prescribed when traditional agents are not effective. Extending follow-up periods, using combination treatments, and considering pulse regimens may also be of benefit. Through these practical techniques, physicians can maximize cure and limit the risk of relapse and re-infection.

In vitro biofilms and antifungal susceptibility of dermatophyte and non-dermatophyte moulds involved in foot mycosis

Tinea pedis and onychomycosis are among the commonest fungal diseases in the world. Dermatophytes and, less frequently, non-dermatophyte moulds are aetiological agents of foot mycosis and are capable of forming biofilms. Fungal biofilm has demonstrated increasing drug resistance. This work aims to evaluate, in vitro, the ability to form biofilm and the susceptibility to antifungal drugs of sessile dermatophytes and non-dermatophyte moulds involved in foot mycosis. Thirty-six dermatophytes and non-dermatophyte moulds isolated from Tunisian patients with foot mycoses, and identified with MALDI-TOF have been tested. MICs of fluconazole, econazole, itraconazole, terbinafine and griseofulvin were carried out using CLSI broth microdilution method. The ability to form biofilm and antifungal activities of drugs against fungal biofilm formation has been quantified by Crystal Violet and Safranin Red staining. Biomass quantification revealed that all species studied were able to form biofilms in vitro after 72 hours. Fluconazole, econazole, itraconazole and terbinafine inhibited fungal growth with MIC values ranging from 0.031 to >64 μg mL^-1 . The best antifungal activity has been obtained with terbinafine against Fusarium solani. Econazole showed the highest activity against fungal biofilm formation. These findings can help clinicians to develop the appropriate therapy of foot mycosis.

Potential of Ravuconazole and its Prodrugs as the New OralTherapeutics for Onychomycosis

Onychomycosis is a fungal infection of the nail apparatus caused by dermatophytes, Candida and non-dermatophytic molds. It is highly prevalent in the general population worldwide and also responsible for significant morbidity and complications and does not usually cure itself. Thus, the condition needs to be treated in view of physical and psychological problems produced. Currently, oral medications using terbinafine are the most effective therapy, but it has relatively limited therapeutic success, particularly for long-term management. Such existing oral therapies are associated with high recurrence rates and treatment failure, as well as with potential adverse events and drug-drug interactions. In the light of these issues, development of more efficacious and safer alternatives for the treatment of onychomycosis is warranted.Ravuconazole and its prodrugs are promising new drug candidates for oral therapy of onychomycosis, among which a water-soluble prodrug, mono-lysine phosphoester derivative (E1224 or BFE1224) is in the most advanced stage of clinical development; a Phase II dose-finding study has been successfully completed and Phase III comparative studies are in progress in Japan.This review aims to summarize our current status of knowledge and information on ravuconazole and its prodrugs, particularly BFE1224, as the potential oral treatment option for onychomycosis. It also summarize the clinical features of onychomycosis with particular stress on its etiology, epidemiology, and current therapeutic options and their limitations. Given its clinical usefulness, BFE1224 may become a valuable addition to the current armamentarium for the treatment of 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.

Tavaborole - a treatment for onychomycosis of the toenails

INTRODUCTION

Onychomycosis is a fungal nail infection that accounts for half of all nail diseases. Oral drugs on the market have adverse effects, while it is difficult for traditional topical drugs to penetrate the nail plate to reach the diseased nail bed. Tavaborole is a new drug that addresses the unmet needs of currently available treatments. Tavaborole (5%) is FDA approved for treating toenail onychomycosis and has shown antifungal activities against yeast, moulds and dermatophytes.

AREAS COVERED

The objective of this article is to review the efficacy, pharmacokinetics, pharmacodynamics, and safety of tavaborole for treatment of toenail onychomycosis. Expert commentary: Tavaborole, with its unique mechanism, may be a good candidate for use in treating children with fungal infections, diabetic individuals, and treating mixed infections. Tavaborole may be paired with other therapies to potentially increase cure rates.

Frequency, type and treatment of fungal pathogens in toenail onychomycosis in the central Alpine region of South Tyrol, northern Italy - a 10-year retrospective study from 2004 to 2013

Onychomycosis is one of the most common dermatological diseases, primarily caused by dermatophytes, and sometimes, also by yeast and moulds. This study aims to clarify the frequency of isolated pathogens from mycotic toenails in the reference centre of the central Alpine mountain region of South Tyrol, northern Italy. Age and gender differences, types of pathogens and initial therapy used were also investigated. This is a retrospective study from 2004 to 2013 on the files of all patients with suspected onychomycosis in whom a cultural pathogen detection was performed. A total of 1565 patients were studied (943 women; 622 men), with a median age of 55 years. Fungal pathogens could be detected by culture in 49.5%. Significantly more pathogens could be grown in men (63.8%) than in women (39.9%, P < 0.0001). The most common pathogens grown were dermatophytes (53.3%), especially T. rubrum and T. interdigitale, followed by moulds (24.7%) and yeast (22%). Therapies prescribed were topical in 64.2% and systemic in 35.8% of the cases. Topical treatment was more frequent in older patients (P < 0.05). In northern Italy, dermatophytes are the most common causative agents for onychomycosis. Fungal pathogens were more commonly found in men than in women and topical treatment was more frequent in older patients.

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.

Safety and efficacy of tinea pedis and onychomycosis treatment in people with diabetes: a systematic review

BACKGROUND

Effective treatment of tinea pedis and onychomycosis is crucial for patients with diabetes as these infections may lead to foot ulcers and secondary bacterial infections resulting in eventual lower limb amputation. Although numerous studies have assessed the effectiveness of antifungal drug and treatment regimens, most exclude patients with diabetes and examine otherwise healthy individuals. While these studies are useful, results cannot necessarily be extrapolated to patients with diabetes. The purpose of this study was to therefore identify the best evidence-based treatment interventions for tinea pedis or onychomycosis in people with diabetes.

METHODS

The question for this systemic review was: 'what evidence is there for the safety and/or efficacy of all treatment interventions for adults with tinea pedis and/or onychomycosis in people with diabetes'? A systematic literature search of four electronic databases (Scopus, EbscoHost, Ovid, Web of Science) was undertaken (6/1/11). The primary outcome measure for safety was self-reported adverse events likely to be drug-related, while the primary outcome measures assessed for 'efficacy' were mycological, clinical and complete cure.

RESULTS

The systematic review identified six studies that examined the safety and/or efficacy of treatment interventions for onychomycosis in people with diabetes. No studies were identified that examined treatment for tinea pedis. Of the studies identified, two were randomised controlled trials (RCTs) and four were case series. Based on the best available evidence identified, it can be suggested that oral terbinafine is as safe and effective as oral itraconazole therapy for the treatment of onychomycosis in people with diabetes. However, efficacy results were found to be poor.

CONCLUSIONS

This review indicates that there is good evidence (Level II) to suggest oral terbinafine is as safe and effective as itraconazole therapy for the treatment of onychomycosis in people with diabetes. Further research is needed to establish the evidence for other treatment modalities and treatment for tinea pedis for people with diabetes. Future efforts are needed to improve the efficacy of treatment intervention.

Pharmacokinetic interaction between itraconazole and metformin in rats: competitive inhibition of metabolism of each drug by each other via hepatic and intestinal CYP3A1/2

BACKGROUND AND PURPOSE

Fungal infection is prevalent in patients with diabetes mellitus. Thus, we investigated whether a pharmacokinetic interaction occurs between the anti-fungal agent itraconazole and the anti-glycaemic drug metformin, as both drugs are commonly administered together to diabetic patients and are metabolized via hepatic CYP3A subfamily in rats.

EXPERIMENTAL APPROACH

Itraconazole (20 mg·kg(-1)) and metformin (100 mg·kg(-1)) were simultaneously administered i.v. and p.o. to rats. Concentrations (I) of each drug in the liver and intestine, maximum velocity (V(max)), Michaelis-Menten constant (K(m)) and intrinsic clearance (CL(int) ) for the disappearance of each drug, apparent inhibition constant (K(i) ) and [I]/K(i) ratios of each drug in the liver and intestine were determined. Also the metabolism of each drug in rat and human CYPs was measured in vitro.

KEY RESULTS

After simultaneous administration of both drugs, either i.v. or p.o., the total area under the plasma concentration-time curve from time zero to infinity (AUC)s of itraconazole and metformin were significantly greater than that of either drug administered alone. The metabolism of itraconazole and metformin was significantly inhibited by each other via CYP3A1 and 3A2 in rat and 3A4 in human microsomes.

CONCLUSIONS AND IMPLICATIONS

The significantly greater AUCs of itraconazole and metformin after i.v. administration of both drugs are probably due to competitive inhibition of the metabolism of each drug by each other via hepatic CYP3A1/2. Whereas after oral administration of both drugs, the significantly greater AUCs of each drug administered together than that of either drug alone is mainly due to competitive inhibition of intestinal metabolism of each drug by each other via intestinal CYP3A1/2.

Pharmacokinetics of itraconazole in diabetic rats

After intravenous or oral administration of 10 mg/kg itraconazole to rats with streptozotocin-induced diabetes mellitus and to control rats, the total area under the plasma concentration-time curve from time 0 to 24 h (AUC0-24) for itraconazole and that for its metabolite, 7-hydroxyitraconazole, were similar between the two groups of rats. This may be explained by the comparable hepatic and intestinal intrinsic clearance rates for the disappearance of itraconazole and the formation of 7-hydroxyitraconazole in both groups of rats.

Dermatological findings in the senior population of nursing homes in Turkey

As the elderly population grows, the problems including skin diseases become more and more frequent. This study involved 300 elderly patients living in 3 nursing homes in Ankara. Their average age was 76.4 years. The average period of time they had lived in the nursing homes was 48.7 months, 25.7% of the cases were bedridden, and 274 cases (91.3%) had at least one systemic disease. Details of the past medical history and the consumed drugs were recorded. The dermatological examination of all cases was performed. Age and sex-dependence of the findings was statistically evaluated, and the risk factors for dermatological diseases were analyzed. The most frequent diseases of the elderly people were: fungal infections and xerosis, with prevalence of 49.7% and 45.3%, respectively. Dermatitis and pruritus were less prevalent (11.0% and 10.3%, respectively). Fungal infections and varicosities were detected more frequently in males, than females. The only risk factor detected for fungal infections was the male sex. We conclude that this study contributes to the identification of the health problems of elderly people, representing a growing proportion of the population in the near future.

Infections in Diabetes Mellitus and Hyperglycemia

Infections in diabetes mellitus are relatively more common and serious. Diabetic patients run the risk of acute metabolic decompensation during infections, and conversely patients with metabolic decompensation are at higher risk of certain invasive infections. Tight glycemic control is of paramount importance during acute infected or high stress state. Infections in diabetic patients result in extended hospital stays and additional financial burden. Given the risks of not alleviating the metabolic dysregulation and the benefits of decent glycemic control, it is necessary that besides antimicrobial therapy, equal emphasis be placed on intensified glycemic control.

Celulitis y onicomicosis proximal de ambos ortejos mayores producida por Fusarium solani

We report a case of proximal fold cellulitis in both big toes, associated with a bilateral proximal onychomycosis and an intertrigo of the fourth space due to Fusarium solani. The infection occurred in an immunocompetent man with diabetes mellitus type II. Apparently, the infection was acquired in a tropical country and once the patient was in Spain the infection progressed causing nail detachment (onychomadesis). Seven months later a relapse that affected the left toenail occurred. The patient was treated topically with chemical toenail avulsion contained 40% urea associated with bifonazole followed by ciclopirox-olamine nail lacquer for 12 months. Complete cure without relapse was observed after 10 years of follow-up. In vitro antifungal susceptibility study demonstrated that two of the recovered isolates were both resistant to itraconazole and voriconazole.

Safety and efficacy of oral terbinafine in the treatment of onychomycosis: Analysis of the elderly subgroup in improving results in ONychomycosis-concomitant lamisil® and debridement (IRON-CLAD), an open-label, randomized trial

OBJECTIVES

The primary objective of this subanalysis was to examine the safety, tolerability, and efficacy of terbinafine in the treatment of toenail onychomycosis in the patients aged > or = 65 years in the Improving Results in Onychomycosis Concomitant Lamisil And Debridement (IRON-CLAD) trial. (Lamisil and IRON-CLAD are trademarks of Novartis Pharmaceuticals Corporation, East Hanover, New Jersey.) The secondary objective was to determine if toenail debridement would provide additional efficacy benefits in this subgroup.

METHODS

The IRON-CLAD trial was an open-label, randomized, multicenter study of adults who underwent 4 weeks of screening and received terbinafine 250 mg/d for 12 weeks with or without aggressive toenail debridement (at baseline and weeks 6, 12, and 24). Clinic visits occurred at weeks 6, 12, 24, and 48. Safety and tolerability were assessed by adverse event (AE) rates based on changes in laboratory values, patient-volunteered information, answers to investigator questions, and physical examinations. Efficacy was evaluated by mycologic cure (negative microscopy of potassium hydroxide samples and negative culture), clinical cure (> or = 87.5% nail clearing), and complete cure (mycologic cure and complete toenail clearing) at week 48. The present subanalysis of IRON-CLAD results assessed participants aged > or = 65 years (older subgroup).

RESULTS

A total of 504 patients were randomized, of whom 75 were aged > or = 65 years. In the older subgroup, the mean (SD) age was 68.9 (3.04), 86.7% (65/75) were white, and 66.7% (50/75) were male. Incidence of AEs reported during the treatment period or within 30 days after treatment discontinuation (treatment-emergent AEs [TEAEs]) was 28.0% in the older subgroup and 23.0% in the overall study population. Most TEAEs were mild (73.7%) to moderate (23.7%) in severity, and most (86.8%) were not suspected by the investigators to be related to study treatment. The most frequently occurring TEAEs in the older subgroup were nausea (4.0%), sinusitis (4.0%) arthralgia (2.7%), and hypercholesterolemia (2.7%). The proportion of participants who withdrew from the trial due to TEAEs was 4.0% (3/75) in the older group and 2.8% (14/504) in the overall population. Only 3 of 11 discontinuations in the older subgroup were due to a TEAE suspected by the investigator to be related to study treatment. Sixty-four percent of the older subgroup took antihypertensive medications, 25% took antidiabetics, and 47% took antilipemic medications. There were no clinical signs of drug interactions in the older subgroup. Clinical efficacy outcomes in the older subgroup were generally good and appeared to be comparable with those in the younger subgroup. At week 48, mycologic cure had occurred in 64.0% (95% CI, 53.1%-74.9%) of the older subgroup, clinical cure in 41.3% (95% CI, 30.2%-52.5%), and complete cure in 28.0% (95% CI, 17.8%-38.2%). Debridement did not appear to affect mycologic outcomes or clinical effectiveness, but rates of clinical and complete cure appeared to be higher among older patients who underwent adjuvant debridement.

CONCLUSIONS

The results of this subanalysis suggest that terbinafine was well tolerated and efficacious in these patients aged > or = 65 years with moderate to severe toenail onychomycosis, many of whom were taking antihypertensives, antidiabetics, or lipid-lowering agents concomitantly. There were no reported clinical signs of drug interactions.