From the Guidelines
For onychomycosis in a patient with eGFR 41, oral terbinafine is not the preferred treatment due to its caution in renal impairment, instead, oral itraconazole as pulse therapy (200 mg twice daily for 1 week per month, for 2 months for fingernails or 3 months for toenails) is a suitable alternative, with no dose adjustment necessary at this eGFR, as per the British Association of Dermatologists' guidelines 1.
Treatment Options
- Oral itraconazole is the preferred treatment, given its first-line recommendation for dermatophyte onychomycosis and the patient's renal function 1.
- The dose for itraconazole is 200 mg per day for 12 weeks continuously, or alternatively as ‘pulse therapy’ at a dose of 400 mg per day for 1 week per month, with monitoring of hepatic function tests recommended 1.
- Topical options like ciclopirox 8% nail lacquer or amorolfine 5% lacquer can be used for mild cases or as adjuncts to oral therapy, with no renal concerns 1.
Monitoring and Follow-up
- Regular liver function monitoring is recommended with oral antifungals, especially itraconazole 1.
- Treatment success should be evaluated by clinical improvement and mycological cure, with follow-up recommended to assess for potential recurrence.
- The patient's moderate renal impairment (eGFR 41) requires caution, but itraconazole is primarily metabolized by the liver, making it a safer choice compared to terbinafine 1.
Key Considerations
- The British Association of Dermatologists' guidelines recommend itraconazole as a first-line treatment for dermatophyte onychomycosis, with a strength of recommendation A 1.
- Terbinafine is generally preferred over itraconazole, but its use is cautioned in patients with renal impairment, making itraconazole a more suitable choice for this patient 1.
From the Research
Treatment Options for Onychomycosis in Patients with Impaired Renal Function
The patient in question has an estimated Glomerular Filtration Rate (eGFR) of 41, indicating impaired renal function. When considering treatment options for onychomycosis in such patients, it is essential to take into account the potential impact of renal impairment on drug efficacy and safety.
Topical Treatment Options
- Efinaconazole 10% topical solution is an FDA-approved treatment for onychomycosis, and its use is recommended for patients with liver or kidney disease 2.
- The pharmacokinetic studies suggest that the efinaconazole topical delivery to the nail bed is not markedly affected by the presence of disease, making it a suitable option for patients with impaired renal function 2.
Oral Treatment Options
- Oral antifungals such as terbinafine and itraconazole are approved for onychomycosis treatment, but their use in patients with impaired renal function requires caution due to potential interactions with cytochrome-p450 and adverse events 3.
- Terbinafine is more effective than other oral antifungals, but its use in patients with renal impairment may require dose adjustment and close monitoring of liver function tests 3, 4.
Other Considerations
- The treatment of onychomycosis in patients with impaired renal function is complex and requires individualized consideration of the patient's needs, adherence, and potential interactions with other medications 5, 6.
- A combination of topical and oral therapies may be considered, but further investigation is needed to determine the most effective approach 4.