From the Guidelines
For fungal nail infections (onychomycosis) that aren't responding to topical cream, the most effective treatment option is oral terbinafine, which should be considered as the first choice based on its higher efficacy and tolerability. According to the British Association of Dermatologists' guidelines for the management of onychomycosis 2014 1, terbinafine is licensed at a dose of 250 mg per day for 6 weeks in fingernail and 12–16 weeks in toenail infection. Several large studies demonstrate higher efficacy rates for terbinafine in comparison with itraconazole, with a multicentre, randomized trial involving 508 subjects showing complete cure in 55% of patients receiving 16 weeks of continuous terbinafine 1.
Some key points to consider when treating onychomycosis include:
- Oral antifungal medications, such as terbinafine and itraconazole, are typically more effective than topical treatments 1
- Terbinafine is generally preferred over itraconazole due to its higher efficacy and tolerability 1
- Topical options, such as ciclopirox 8% nail lacquer, may be useful for superficial and distal onychomycosis or for patients in whom systemic therapy is contraindicated 1
- Nail removal (avulsion) may be considered for severe cases, either partially or completely, sometimes combined with oral medication
- Before starting any new treatment, confirmation of the diagnosis through nail clipping for microscopy and culture is recommended, as other conditions can mimic fungal infections 1
It's also important to note that complete nail clearing takes time, as the healthy nail needs to grow out, which can take 9-12 months for toenails and 4-6 months for fingernails. Patients should be advised of this and monitored regularly to assess treatment response and potential adverse effects, such as headache, taste disturbance, and gastrointestinal upset, which are common with oral antifungal medications 1.
From the FDA Drug Label
Prior to initiating treatment, appropriate nail specimens for laboratory testing (KOH preparation, fungal culture, or nail biopsy) should be obtained to confirm the diagnosis of onychomycosis The patient's current cream treatment is not working, and the options for treating onychomycosis of the fingernail include:
- Terbinafine (PO): One 250 mg tablet once daily for 6 weeks 2 It is essential to confirm the diagnosis of onychomycosis through laboratory testing before initiating treatment with Terbinafine (PO) 2
From the Research
Fungal Infection Treatment Options
If the cream provided is not effective in treating the fungal infection on the fingernail, there are several oral antifungal options available.
- Terbinafine, itraconazole, and fluconazole are effective treatments for onychomycosis, with terbinafine being the most frequently prescribed oral antifungal agent in the US and Canada 3.
- The choice of treatment depends on the type of fungus causing the infection, with terbinafine being more effective against dermatophytes and itraconazole being more effective against Candida and nondermatophyte infections 4, 5.
- The treatment regimens for these oral antifungals vary, with terbinafine typically given as a continuous once-daily therapy for 12 weeks, and itraconazole given as pulse therapy with the drug being administered for 1 week with 3 weeks off treatment between successive pulses 4.
Safety and Efficacy
- Oral antifungals have several interactions with cytochrome-p450, which can facilitate adverse events, and laboratory testing of liver function tests is recommended prior to administration 6.
- Terbinafine, itraconazole, and fluconazole have a good safety profile, but can cause adverse reactions such as gastrointestinal distress, cutaneous eruption, and CNS effects 4, 5.
- The efficacy of these treatments has been established in many studies, with terbinafine showing a high mycological cure rate of 76% +/- 3% in the treatment of dermatophyte toenail onychomycosis 3.
Treatment Failure
- In the event of a first treatment failure, the diagnosis of onychomycosis must be confirmed, and consideration given to antifungal susceptibility testing 6.
- Antifungal stewardship is important to reduce the incidence of antifungal resistance, and alternative treatments may be considered in cases of treatment failure 6.