Pharmacoeconomic analysis of the new oral antifungal agents used to treat toenail onychomycosis in the USA

Patient considerations in the management of toe onychomycosis - role of efinaconazole

Onychomycosis is a difficult diagnosis to manage and treatment is sometimes avoided, as this diagnosis is often wrongly perceived as a cosmetic problem. However, onychomycosis has a negative impact on patients' quality of life, affecting social interaction, psychological well-being, and physical activities. Onychomycosis is also a risk factor for patients with diabetes, with proven increased rates of cellulitis, gangrene, and foot ulcers. Treatments are only mild to moderately effective, and rates of relapse and reinfection are high. Oral treatments require laboratory monitoring due to risk of hepatotoxicity and may be contraindicated in some patients due to risk of drug-drug interactions. Topical treatments require prolonged application and are not very effective. Efinaconazole 10% solution is a new topical triazole treatment for mild to moderate distal subungual onychomycosis, with good efficacy and without the need for debridement of nails. In onychomycosis of the toenails, efinaconazole 10% solution is documented to have a statistically significant, positive impact on patient satisfaction and quality of life.

Systematic review of severe acute liver injury caused by terbinafine

BACKGROUND

Terbinafine is an effective antimicrobial agent against dermatophytes, cryptococcus and other fungi. It is the preferred drug to treat onychomycosis. However, severe acute hepatitis from oral terbinafine administration has been recently reported.

AIM

To describe a representative case, and review the literature regarding the best evidence on treatment and prognosis of severe acute hepatitis caused by oral terbinafine.

METHODS

The literature was searched for publications on severe hepatitis caused by terbinafine using MEDLINE, China Biology Medicine Disc, and the VIP Medical Information Resource System. Related references were searched manually.

RESULTS

Seventeen English and three Chinese references of case reports were included after eliminating duplicate publications. No randomized control studies were found. Liver enzyme levels were found to have been increased significantly. Abdominal ultrasound demonstrated cholestasis.

CONCLUSIONS

Severe acute liver injury is a known, but unusual complication of terbinafine exposure. The prognosis is often good with appropriate treatment. Liver function assessment before treatment and periodic monitoring 4-6 weeks after initiation of treatment is recommended.

Systematic review of severe acute liver injury caused by terbinafine

BACKGROUND

Terbinafine is an effective antimicrobial agent against dermatophytes, cryptococcus and other fungi. It is the preferred drug to treat onychomycosis. However, severe acute hepatitis from oral terbinafine administration has been recently reported.

AIM

To describe a representative case, and review the literature regarding the best evidence on treatment and prognosis of severe acute hepatitis caused by oral terbinafine.

METHODS

The literature was searched for publications on severe hepatitis caused by terbinafine using MEDLINE, China Biology Medicine Disc, and the VIP Medical Information Resource System. Related references were searched manually.

RESULTS

Seventeen English and three Chinese references of case reports were included after eliminating duplicate publications. No randomized control studies were found. Liver enzyme levels were found to have been increased significantly. Abdominal ultrasound demonstrated cholestasis.

CONCLUSIONS

Severe acute liver injury is a known, but unusual complication of terbinafine exposure. The prognosis is often good with appropriate treatment. Liver function assessment before treatment and periodic monitoring 4-6 weeks after initiation of treatment is recommended.

Onychomycosis: beyond cosmetic distress

Onychomycosis, or fungal infection of the nail, is the most common nail disease affecting children (although to a lesser extent) as well as adults. The distress it provokes is not only of a cosmetic kind; it may impair the quality of life. The different clinical types of onychomycosis should be differentiated from similar-looking nail diseases. As far as therapy is concerned, the appearance of new antifungal drugs in the 1990s makes our job easier, but it does not allow us to cure 100% of the patients. Relapses still exist. The aim of this article is to help dermatologists achieve a tailor-made treatment for their patients. The clinical type, the compulsory mycological investigations, the age of the patient, his medical history (drug intake), as well as the use of nail cosmetics, must be considered.

Use of terbinafine for tinea in Australian Aboriginal communities in the Top End

Tinea of the skin and nails is a common problem in remote Aboriginal communities of the Top End of Australia. A retrospective study was performed on data collected from 104 patients from several indigenous communities. Worksheets were filled in by district medical officers and rural general practitioners, detailing the extent of the tinea. Patients were prescribed between 4 and 12 weeks of 250 mg daily oral terbinafine. Fifty-two patients were followed up, with 45 having a good response to treatment (87%) and with 22 of these patients having full clearance of tinea (42%). A prospective study with 44 subjects was performed. The extent of the tinea was documented and fungal scrapings/clippings were taken. Forty subjects were recruited and given oral terbinafine (2-12 weeks depending on skin/nail involvement) or topical terbinafine if oral treatment was contraindicated. Twenty-five of the 40 (63%) subjects were reviewed. Twenty-three (92%) subjects that were followed up improved clinically, with 8/25 (32%) clearing completely. Twenty (80%) of followed-up patients complied fully with treatment. Terbinafine was found to be a well-tolerated and effective treatment of tinea of the skin and nails.

Onychomycosis: current treatment options

PURPOSE

To describe current evidence regarding the treatment of clients with onychomycosis who have one or more chronic illnesses.

DATA SOURCES

Current review of research articles, standard pharmaceutical texts, and case studies.

CONCLUSIONS

Onychomycosis is often considered only as a cosmetic diagnosis. Treatment is based on factors such as the client's willingness to pay for expensive therapy and the ability to physically comply with daily regimens; however, treatment of onychomycosis in clients with chronic illnesses including diabetes and peripheral vascular disease should be strongly encouraged. For these clients, onychomycosis is not just a cosmetic diagnosis because it has the potential to decrease mobility and blood flow to the affected digits if left untreated.

IMPLICATIONS FOR PRACTICE

The primary care clinician's successful management of client's with chronic illnesses such as diabetes and peripheral vascular disease should include the treatment of onychomycosis. Recognizing the best treatment is a crucial decision.

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.

An open, randomized, comparative study of oral fluconazole, itraconazole and terbinafine therapy in onychomycosis

BACKGROUND/AIM

In this open, randomized and comparative study, the safety and efficacy of systemic fluconazole, itraconazole and terbinafine was investigated in 50 patients with distal subungual toenail onychomycosis diagnosed clinically and mycologically. The patients with positive mycology and also the patients with positive microscopy and negative culture were investigated.

METHODS

The treatment duration was 3 months, and the follow-up period was 6 months. Patients were randomly assigned: 16 patients received 150 mg fluconazole once weekly, 18 patients received 200 mg itraconazole twice daily with meals during the first week of each month, and 16 patients received 250 mg/day terbinafine during the treatment period.

RESULTS

In a clinical evaluation, at the endpoint of the follow-up period, the clinical cure rates were 81.3% (13/16) in the terbinafine group, 77.8% (14/18) in the itraconazole group, and 37.5% (6/16) in the fluconazole group. The mycological cure rates were 75% (12/16), 61.1% (11/18) and 31.2% (5/16), respectively. The overall assessment rates were 62.5% (10/16), 61.1% (11/18) and 31.2% (5/16), respectively. Statistically significant intra-group reductions from baseline symptom severity values were seen at the endpoint of treatment and at the endpoint of the follow-up period for all three treatment groups in onycholysis, subungual hyperkeratosis, affected-area percentage score and total score parameters (p < 0.001). At the endpoint of the follow-up period, statistically significant differences between the treatment groups were seen in clinical, mycological and overall assessment (p < 0.05). However, while no statistically significant difference between the terbinafine and itraconazole groups was seen, there was a clinical and statistical difference between the other groups and the fluconazole group. Treatment was not stopped for side effects such as mild gastrointestinal and central nervous system symptoms. These effects were noted in four patients in the fluconazole group (25%), five patients in the itraconazole group (27.8%), and three patients in the terbinafine group (18.75%). The clinical laboratory data on all three drug groups did not show any statistically or clinically significant intra-group changes from baseline values at the endpoint (p > 0.05).

CONCLUSION

This comparative study of systemic fluconazole, itraconazole and terbinafine showed that all three drugs were effective and safe in the treatment of onychomycosis. However, fluconazole, at these doses and treatment durations, was the least effective. With regard to cost-effectiveness, side effects and the cure rates, terbinafine could be the drug of choice in the short-term treatment of toenail onychomycosis.

Pharmacoeconomic analysis of ciclopirox nail lacquer solution 8% and the new oral antifungal agents used to treat dermatophyte toe onychomycosis in the United States

BACKGROUND

Recently a novel topical nail lacquer, ciclopirox solution 8%, has been approved for the treatment of onychomycosis.

OBJECTIVE

This was undertaken to determine the most cost-effective treatment for the treatment of dermatophyte onychomycosis of the toes in the United States in 2000.

METHODS

The nature of the problem was defined. The drug comparators were ciclopirox nail lacquer, terbinafine, itraconazole (pulse), itraconazole (continuous), fluconazole, and griseofulvin. A decision analytic model that reflected the manner in which pedal tinea unguium is managed was produced. Studies that have evaluated the efficacy of the nail lacquer and the oral antifungal agents for this indication were identified. Appropriate studies were used in a meta-analysis to determine the mycologic and clinical response rates when the drug comparators are used for the treatment for toe dermatophyte onychomycosis. For each drug comparator a cost of regimen analysis was carried out. This is the sum of the drug acquisition cost, the cost of medical management, and the cost of managing adverse effects. Next, the expected cost of management was calculated, disease free days were determined, and a sensitivity analysis was conducted.

RESULTS

For each comparator the meta-analytic average mycologic cure (MC) rate and clinical response (CR) rates were: ciclopirox nail lacquer (MC: 52.6 +/- 4.2%, CR: 52.4 +/- 9.0%), griseofulvin (MC: 41.1 +/- 20.4%, CR: 33.7 +/- 14.1%), itraconazole (continuous) (MC: 66.3 +/- 4.2%, CR: 70.3 +/- 4.2%), itraconazole (pulse) (MC: 70.8 +/- 5.7%, CR: 73.6 +/- 4.6%), terbinafine (MC: 77.2 +/- 4.0%, CR: 75.3 +/- 2.9%), and fluconazole (MC: 65.6 +/- 7.1%, CR: 66.5 +/- 11.7%). The cost of regimen for the drug comparators was: ciclopirox nail lacquer $325.2, griseofulvin $1413.1, itraconazole (continuous) $1410.2, itraconazole (pulse) $811.7, terbinafine $890.1, and fluconazole $966.8. The cost/mycologic cure rate and expected cost/expected symptom free day were, ciclopirox nail lacquer ($618.2, 1.69), griseofulvin $3438.2, 5.3), itraconazole (continuous) ($2126.9, 3.52), itraconazole (pulse) ($1146.4, 2.01), terbinafine ($1153.0, 2.14), and fluconazole ($1473.7, 2.10). The relative cost-effectiveness was ciclopirox nail lacquer 1.00, itraconazole (pulse) 1.19, fluconazole 1.24, terbinafine 1.27, itraconazole (continuous) 2.08, and griseofulvin 3.13. Sensitivity analysis indicated that ciclopirox nail lacquer was a cost effective alternative compared with the oral regimens of terbinafine, itraconazole (continuous), and griseofulvin when clinical response rate was used as the primary efficacy parameter.

CONCLUSION

Ciclopirox nail lacquer solution 8% is a recent addition to the armamentarium of therapies available to the physician and patient for the treatment of onychomycosis. The nail lacquer is a cost effective agent compared with the oral antifungal therapies, terbinafine, itraconazole, fluconazole, and griseofulvin.

Current Management of Onychomycosis and Dermatomycoses

Three newer oral antifungal agents, itraconazole, terbinafine and fluconazole, have revolutionized treatment of superficial mycoses. The tissue pharmacokinetics of itraconazole and terbinafine allow much shorter courses of therapy- with higher efficacy-in the treatment of onychomycosis, compared to other oral agents. Itraconazole pulse dosing and terbinafine daily dosing have shown comparable efficacy against dermatophyte onychomycosis; similar itraconazole regimens have been effective against nondermatophyte infections. Refractory clinical patterns of nail disease appear to be more responsive to oral antifungal therapy when combined with adjunctive therapy, such as debridement. These agents are effective against cutaneous dermatophytosis, with shorter treatment regimens. Tinea versicolor may be treated with a single-dose, intermittent, or daily regimen of an oral azole agent, depending on the drug selected. These newer oral antifungal agents have been proven effective against tinea capitis; effective regimens are shorter than those for griseofulvin. The safety profile of these newer agents has been very favorable.

Onychomycosis in the elderly

Onychomycosis is found more frequently in the elderly, and in more males than females. Onychomycosis of the toes is usually caused by dermatophytes, most commonly Trichophyton rubrum and T. mentagrophytes. The most common clinical presentations are distal and lateral subungual onychomycosis (which usually affects the great/first toe) and white superficial onychomycosis (which generally involves the third/fourth toes). Only about 50% of all abnormal-appearing nails are due to onychomycosis. In the remainder, trauma to the nail, psoriasis and conditions such as lichen planus should be considered in the differential diagnosis. Therefore, the clinical impression of onychomycosis should be confirmed by mycological examination, whenever possible. The management of onychomycosis may include no therapy, palliative treatment with mechanical or chemical debridement, topical antifungal therapy, oral antifungal agents or a combination of treatment modalities. In the US, the only new oral agents approved for treatment of onychomycosis are terbinafine and itraconazole. Fluconazole is approved for onychomycosis in some other countries. Ciclopirox nail lacquer has recently been approved in the US for the treatment of onychomycosis. In some other countries topical agents such as amorolfine are also used. Griseofulvin and ketoconazole are no longer preferred for the treatment of onychomycosis. The new oral antifungal agents are effective and well tolerated in the elderly. Patient selection should be based on the history (including systems review and medication record), examination and baseline monitoring, if indicated. Laboratory monitoring during therapy for onychomycosis varies among physicians. A combination of removal of the diseased nail plate or local measures and oral antifungal therapy may be optimal in certain instances, e.g. when lateral onychomycosis or dermatophytoma are present. For dermatophyte toe onychomycosis the recommended duration of therapy with terbinafine is 250 mg/day for 12 weeks. For itraconazole (pulse) the regimen is 200 mg twice daily for 1 week on, 3 weeks off, repeated for 3 consecutive pulses and with fluconazole the regimen is 150 to 300 mg once weekly given for a usual range of 6 to 12 months or until the nail plate has grown out. In some instances, if extra therapy is required, one suggestion is that 4 weeks of terbinafine or an extra pulse of itraconazole are given between months 6 and 9 from the start of therapy. Once cure has been achieved, it is important to counsel patients on the strategies of reducing recurrence of disease.