Pharmacy Technicians and Improving Onychomycosis Treatment Outcomes

Abstract

Objective: To provide an overview of onychomycosis and current treatments and to identify opportunities for pharmacy technicians to improve treatment outcomes. Data Sources: A MEDLINE/PubMed search (1966 to October 2018) was performed using search terms designed to identify English-language articles on onychomycosis diagnosis, treatment, and prevention, as well as articles on the impact of pharmacy technicians on onychomycosis outcomes and the use of pharmacy technicians to improve treatment adherence. Study Selection and Data Extraction: Review articles and clinical studies describing onychomycosis, risk factors, treatment efficacy, and prevention of recurrent infections were included. Data Synthesis: Although no articles on the impact of pharmacy technicians in the treatment of onychomycosis were found, the importance of treatment adherence on positive outcomes highlights a potential role of pharmacy technicians. Pharmacy technicians can identify patients with potential onychomycosis based on questions about over-the-counter products and refer patients to the pharmacist for counseling on treatment. Pharmacy technicians can also reinforce treatment adherence at refill visits. Conclusions: Pharmacy technicians can have a positive impact on onychomycosis treatment outcomes by addressing barriers to successful treatment and promoting treatment adherence.

Introduction

Onychomycosis is a common fungal infection of the nail plate, infecting approximately 1 in 10 people in the United States.¹ Onychomycosis accounts for one third of fungal skin infections and up to 40% of nail diseases.¹ The incidence of nail fungal infections has been increasing in recent years, likely due to use of occlusive footwear and increasing popularity of sports and gym use.^2,3

Although usually considered a cosmetic issue, onychomycosis can negatively affect quality of life.⁴ The nail infection can cause pain and difficulty walking, leading to limited mobility especially in older patients.³ The changes in nail appearance may result in the patient’s avoidance of public areas and a negative self-image.⁴

Although several treatments are available for onychomycosis, poor treatment adherence (<25%) and long treatment durations often result in poor outcomes such as relapse and reinfection.^5,6 Pharmacy technicians can improve onychomycosis outcomes by referring patients to the pharmacist for treatment selection and educating patients on treatment expectations. Technicians can also reinforce treatment adherence when patients come to the pharmacy for medication refills.

The objectives of this review are to provide pharmacy technicians with an overview of onychomycosis, its treatments, and potential barriers to positive treatment outcomes. Additionally, roles for pharmacy technicians to promote positive onychomycosis outcomes will be discussed.

Data Sources

English-language articles on onychomycosis and onychomycosis treatment were identified through searches conducted using MEDLINE/PubMed (1966 to October 2018). The keywords “onychomycosis,” “onychomycosis treatment,” and onychomycosis prevention” were used in addition to the following medical subject headings: “Onychomycosis/complications,” “Onychomycosis/drug therapy,” “Onychomycosis/prevention and control,” and “Onychomycosis/therapy.” “Pharmacist,” “pharmacy technician,” and “pharmacy” were used to locate articles addressing the impact of pharmacists and pharmacy technicians on onychomycosis treatment outcomes. Reference lists of relevant articles were searched for additional sources. In addition, articles on the role of pharmacy technicians in community pharmacy practice were identified using the keywords “pharmacy technician,” “community pharmacy,” “advanced community pharmacy practice,” “adherence,” “patient education,” and “treatment adherence.” The goal of this review was to highlight the importance of medication adherence and patient education in the management of onychomycosis and how pharmacy technicians can assist pharmacists with addressing these issues.

Results

No studies were found that addressed the role of pharmacy technicians or pharmacists in the treatment or prevention of onychomycosis. Only one study evaluated community pharmacy personnel, including pharmacy technicians, and their views on managing dermatological issues.⁷ Twenty-three articles concerned the diagnosis and/or treatment of onychomycosis,^1-6,8-23 including 1 guideline.²⁴ Three articles focused on risk factors and prevention of recurrent infection.^5,25,26 Seven studies evaluated the use of pharmacy technicians in advanced roles and as part of team-based interventions.^27-33

Pathophysiology and Clinical Presentation of Onychomycosis

Onychomycosis occurs when the fungus invades the nail plate and/or nail bed and begins to destroy the nail.^4,8 The fungus is typically a local infection but may spread to the nail via the vascular or lymphatic systems.⁹ The most common organisms implicated in onychomycosis are dermatophytes, such as Tricophyton species, Microsporum species, Epidemophyton floccosum, or Fusarium species. Other organisms include Candida yeast and non-dermatophyte molds. Different types of onychomycosis are usually identified by the location of the infection.⁹ Table 1 describes the types of onychomycosis.

Table 1.

Types of Onychomycosis.

Type of Onychomycosis	Infection Location	Comments
Distal lateral subungual onychomycosis	Starts at distal or lateral edge of nail10	Most common type, especially in children10,11
Endonyx subungual onychomycosis	Only involves nail plate8
Proximal subungual onychomycosis	Starts at proximal edge of nail near cuticle and extends distally9	May be secondary to skin infection; usually requires oral antifungal therapy9
Superficial onychomycosis	Involves upper layers of nail plate9	Topical antifungal therapy is more likely to be effective due to superficial infection; uncommon in children9,11
Mixed-pattern onychomycosis	Different clinical patterns in same nail9	Requires oral antifungal therapy9
Total systrophic onychomycosis	Involves entire nail and surrounding skin9	Often the end stage of onychomycosis9
Secondary onychomycosis	Any location already described above9	Secondary to psoriasis and traumatic nail dystrophy9

Onychomycosis can also occur secondary to other nonfungal conditions, such as psoriasis or traumatic nail dystrophy. The appearance of the nail in secondary onychomycosis depends on the initial condition.⁹ Treatment of the underlying condition is recommended in conjunction with antifungal therapy to effectively treat secondary onychomycosis.

Onychomycosis Risk Factors

While onychomycosis can occur in patients of all ages, the incidence is higher in older populations. Fungal nail infections have been reported in up to 28% of adults over the age of 50.^1,3 Onychomycosis is uncommon in children, possibly due to rapid nail growth and smaller nails.³ Men are more likely to develop onychomycosis. The reason is unclear, but the gender difference has been attributed to different hormone effects on fungal inhibition and a higher likelihood of nail injuries.⁷ Susceptibility to onychomycosis may have a genetic component since patients with distal lateral subungual onychomycosis often have at least one parent with onychomycosis.^8,25,26

An increased risk of onychomycosis has been associated with chronic diseases that affect circulation, notably diabetes and peripheral arterial disease.^{8,12,13,25,26} For patients with diabetes, the combination of poor circulation, diabetic neuropathy, and impaired wound healing also increases the risk of onychomycosis complications.⁸ Decreased circulation due to peripheral arterial disease also predisposes patients to onychomycosis and related complications.^8,13

Immunodeficiency in patients with HIV infection, transplant recipients, and those on immunosuppression therapies can lead to onychomycosis,^8,14,24,25 especially due to spread of fungi through the vasculature or lymphatic system.⁹ Onychomycosis has also been reported more commonly in patients with psoriasis.^3,25

Some risk factors for onychomycosis are modifiable. Smoking can decrease circulation to extremities, and like diabetes and peripheral arterial disease, can slow nail growth and increase the likelihood of fungal infection of the nail. Therefore, smoking cessation may decrease the risk of onychomycosis.¹³ Because onychomycosis is communicable, shared living quarters and communal bathing facilities contribute to the spread of infection to others.² Sports and physical activity can cause nail trauma, and walking barefoot in locker rooms and public shower facilities also increases the risk of onychomycosis.^24,26

Onychomycosis Treatments

Over-the-Counter Treatments

While over-the-counter (OTC) treatments are available for onychomycosis, little evidence beyond anecdotal reports is available to support their routine use. Most OTC agents only soften the nail, which permits easier nail trimming and removal of rough, flaky nail material.¹⁵ OTC products have limited effectiveness due to lack of nail penetration, and most have not been compared with either oral or topical prescription antifungal agents.¹⁵ Small clinical studies with mentholated ointment (Vicks VapoRub) and tea tree oil (Melaleuca alternaifolia) reported clinical cure rates of approximately 20%, which is lower than reported with prescription products.^16,17 Snakeroot extract (Ageratina pichinchensis) is also an option, with clinical and mycologic cure rates similar to ciclopirox (a prescription topical antifungal agent).¹⁸

Oral Prescription Antifungal Medications

Oral medications that are Food and Drug Administration approved for onychomycosis treatment are terbinafine and itraconazole.^34,35 Fluconazole, while not Food and Drug Administration approved for onychomycosis, has been studied for this indication and is an option for treatment.³⁶ Oral agents are typically given once daily for 12 weeks for toenail infections, but pulse therapy can be used with itraconazole when the infection is limited to fingernails.^34,35 With pulse therapy, the itraconazole capsules are taken for 1 week followed by 3 weeks of no treatment and then 1 more week of treatment.³⁴ If fluconazole is used, the treatment duration is longer, with treatment required for at least 6 months.¹⁹

Oral antifungal treatments are associated with a mycologic cure rate up to 70% for toenail infections and up to 79% for fingernail infections (mycologic cure = negative microscopic exam for fungal elements and negative fungal culture). Complete cure rates, however, are much lower with rates reported up to 38% for onychomycosis of the toenail and up to 59% for fingernail onychomycosis (complete cure = mycologic cure and no clinical signs of infection).^19,34,35 These cure rates assume that the patient has good adherence to the treatment. In patients with poor adherence, the cure rates can be as low as 2%.⁵

Use of oral antifungal medications may be limited by their associated adverse effects and potential drug interactions, particularly in patients already on multiple medications. All 3 oral agents can cause elevations in liver enzymes and hepatic injury.^34-36 Itraconazole and fluconazole, like other azole antifungal agents, can prolong the QT interval and cause cardiac arrhythmias, including torsades de pointes.^34,36 Hypersensitivity skin reactions are also possible with terbinafine and fluconazole, so patients should be educated about signs of toxic epidermal necrolysis and Stevens-Johnson syndrome.^35,36

All 3 oral agents are metabolized by cytochrome P450 (CYP) enzymes and may interact with many different medications.^34-36 Providers should check for drug interactions prior to prescribing and dispensing an oral antifungal medication. Also, because itraconazole and fluconazole may increase the QT interval, caution should be used in patients on other medications that prolong the QT interval.^34,36 Gastric acidity is required for absorption of itraconazole, so drugs that decrease gastric acid, such as proton pump inhibitors and H2 antagonists, will decrease absorption and efficacy of itraconazole.³⁴

Topical Prescription Antifungal Medications

Three topical agents have been approved for treatment of onychomycosis—ciclopirox, tavaborole, and efinaconazole. All 3 are applied to the nail plate of affected nails daily until the nail has completely grown out, which is 48 weeks for toenails.^37-39 While the treatment duration is a disadvantage to the use of topical onychomycosis treatments, the advantages are few adverse effects and no drug interactions. The only adverse effect reported with these agents is localized irritation of the skin around the nail and ingrown toenails. Because the topical medications are not systemically absorbed, interactions with other medications have not been reported.^37-39

Topical treatments are not as effective as the oral antifungal medications. With topical agents, mycologic cure occurs in up to 55% of patients, while complete cure rates are less than 18%.^37-39 The lack of penetration through the nail plate is one reason for the lower efficacy, and cure rates may improve with increased nail penetration. Some strategies for enhancing nail penetration include debridement of the nail, chemical avulsion of the nail, iontophoresis, and microporation of the nail.⁵

Nonpharmacologic Treatments

Nonpharmacologic treatments are available to treat onychomycosis. Although surgical removal of the infected nail has been evaluated in clinical trials, this option is not recommended.^20,24 Laser therapy allows treatment of the affected area of the nail and penetrates the nail plate and may be useful in milder cases of onychomycosis (<65% nail involvement); however, the laser can damage healthy tissue due to excessive heat.^21,22 Photodynamic therapy is another option, but low efficacy rates, residual nail changes after treatment, and pain with treatment limit its use for onychomycosis.²¹

Barriers to Positive Outcomes

One of the main barriers to a positive treatment outcome in patients with onychomycosis is poor adherence. With both oral and topical antifungal treatments, adherence rates in clinical studies are low—about 45% with oral agents and 24% with topical medications.⁵ Patients who have good adherence are more likely to have better cure rates when compared with patients with poor adherence. Cure rates with topical antifungal treatment was 63% with good adherence, but only 2% with poor adherence in one clinical study.⁵ Poor adherence may be due to the long treatment durations required for onychomycosis therapy, especially topical treatments.^5,23 Patients who have tried OTC medications may have had a less than satisfactory experience and be reluctant to try a prescription treatment. Another reason for poor adherence is the potential adverse effects and drug interactions with oral medications.

The cost of onychomycosis treatment can be a major barrier for many patients. The newer topical agents can be expensive, especially considering that the patient will need to use these agents for an entire year.²⁶ Itraconazole and terbinafine are available as generic medicines and are much cheaper for patients who can tolerate the oral agents and who are not on other drugs, which may interact with the antifungal drugs.⁵

Recurrent infections are common in patients with onychomycosis, occurring in up to 50% of patients.⁵ Onychomycosis can recur due to relapse from inadequate treatment or reinfection by the same or different fungal species. Relapses usually occur within 3 years of treatment. Strategies to prevent recurrence include prophylactic topical antifungal treatment, management of modifiable risk factors, and decontamination of footwear.^5,26 Twice-weekly application of topical antifungals has been recommended for prophylaxis of recurrent infections. Good foot hygiene will keep the foot dry by not walking barefoot in damp places such as communal bathing facilities. Smoking cessation, proper-fitting footwear, and disinfection of nail clippers will also decrease the risk of reinfection. Footwear should be allowed to dry out completely after wear. Washable shoes can be cleaned in hot water (>140°F or 60°C) to eliminate the fungus.^5,26

Discussion

Although no studies have specifically evaluated the role of pharmacy technicians in onychomycosis treatment, other studies have shown the benefits of utilizing pharmacy technicians for improving outcomes in other disease states, such as hypertension and diabetes.^29,30 Pharmacy technicians can identify patients at risk for poor adherence and adverse reactions.^29-31 The use of a team approach involving pharmacy technicians can improve refill rates and adherence.^29,30

Because patients are likely to come to the pharmacy for advice and products for treating onychomycosis and other dermatologic issues,⁷ pharmacy technicians can assist patients by referring them to the pharmacist for detailed discussions on treatment options and by reinforcing treatment adherence.²⁷ When patients are first seen in the foot care aisle, pharmacy technicians can validate patient’s concerns about their condition and help encourage patients to follow the pharmacist’s advice. If allowed in their state, pharmacy technicians can counsel patients on the different OTC treatments for fungal infections and educate them on the efficacy of those treatments.²⁷ Pharmacy technicians can also direct patients toward educational materials on onychomycosis pathophysiology, treatment expectations, foot hygiene, and prevention of recurrent infection.²⁷

Medication cost should be discussed with the patient prior to filling a prescription for onychomycosis, particularly with the newer topical drugs.²⁶ The manufacturers of these medications do offer cost assistance programs to help patients without prescription coverage or those whose insurance does not cover onychomycosis therapy. Pharmacy technicians can also assist patients with insurance claims.

When patients come to the pharmacy to fill and pick up their antifungal treatments, pharmacy technicians can ask about adherence and reinforce the importance of treating the infection for the entire treatment period, especially with topical therapies.²⁶ While the pharmacist will provide detailed explanations of onychomycosis treatment options and expectations, pharmacy technicians can support the pharmacist by triaging patient questions and concerns.²⁷ In addition, the technician can encourage the patient throughout treatment.

This review is limited by the lack of available literature. Articles on onychomycosis focus on the pathophysiology, diagnosis, and treatment of the infection; however, studies on how different health care professionals, such as pharmacy technicians, can affect onychomycosis outcomes were not found. Future research on the role of pharmacy technicians in improving onychomycosis treatment adherence and outcomes is needed.

Conclusion

Onychomycosis is a common nail disease, but it is often seen as a cosmetic issue instead of a serious fungal infection. Because of the potentially long treatment duration, low adherence rates, and risk of complications and recurrence, pharmacy technicians can assist patients with cost concerns and adherence improvement. Selected articles included 25 on onychomycosis diagnosis and treatment and 7 addressing pharmacy technician roles. Only one article that mentioned pharmacy technicians in the context of onychomycosis and other dermatological issues was found. Although literature on the role of pharmacy technicians in onychomycosis treatment is lacking, pharmacy technicians may be able to assist the pharmacist in positively affecting onychomycosis treatment outcomes.