From the Guidelines
For a patient with ringworm where ketoconazole is not working, switching to terbinafine (Lamisil) 250mg daily for 2-4 weeks is the most effective treatment option, as it has good evidence of efficacy against Trichophyton species, which are common causes of ringworm 1. When considering treatment options, it's essential to note that topical therapy alone is not recommended for the treatment of tinea capitis, and oral therapy is generally indicated to achieve both clinical and mycological cure 1.
- The choice of systemic therapy should be directed by the causative dermatophyte and/or local epidemiology 1.
- Terbinafine requires a shorter course of treatment, which may increase compliance, and it is more efficacious against Trichophyton species 1.
- In cases of treatment failure, it's crucial to consider lack of compliance, suboptimal absorption of the drug, relative insensitivity of the organism, and reinfection, and to proceed to second-line therapy if necessary 1.
- Itraconazole is a safe and effective second-line therapy option, with activity against both Trichophyton and Microsporum species, and can be used at a dose of 50–100 mg per day for 4 weeks, or 5 mg kg−1 per day for 2–4 weeks 1.
- Preventing reinfection is also crucial, and this can be achieved by washing bedding and clothes in hot water, avoiding sharing personal items, keeping skin dry, and treating any infected pets.
From the FDA Drug Label
DOSAGE & ADMINISTRATION SECTION Cutaneous candidiasis, tinea corporis, tinea cruris, tinea pedis and tinea (pityriasis) versicolor: It is recommended that Ketoconazole Cream 2% be applied once daily to cover the affected and immediate surrounding area Clinical improvement may be seen fairly soon after treatment is begun; however, candidal infections and tinea cruris and corporis should be treated for two weeks in order to reduce the possibility of recurrence. Patients with tinea versicolor usually require two weeks of treatment. Patients with tinea pedis require six weeks of treatment If a patient shows no clinical improvement after the treatment period, the diagnosis should be redetermined.
The patient has ringworm, which is also known as tinea corporis. According to the label, tinea corporis should be treated for two weeks.
- If the patient has been using ketoconazole for less than two weeks, it may be too early to determine if the treatment is working.
- If the patient has been using ketoconazole for two weeks or more and shows no clinical improvement, the diagnosis should be redetermined 2.
From the Research
Alternative Treatment Options
If ketoconazole is not working for a patient with ringworm, there are alternative treatment options available.
- Terbinafine has been shown to be more effective than griseofulvin in some studies 3, 4.
- Itraconazole has also been found to be effective in treating tinea infections, with some studies suggesting it is more effective than terbinafine 5, 6.
- Fluconazole is another option, although its effectiveness may vary depending on the specific type of infection and the patient population 4, 6.
Comparison of Treatment Options
Studies have compared the effectiveness of different oral antifungal drugs, including:
- A study found that itraconazole was superior to fluconazole, griseofulvin, and terbinafine in treating chronic and chronic relapsing tinea corporis, tinea cruris, and tinea faciei 6.
- Another study found that terbinafine and itraconazole were effective in treating tinea infections, with terbinafine being more effective than griseofulvin 3.
- A review of the literature found that ketoconazole was the first broad-spectrum, oral antifungal drug to be used in clinical medicine, but its effectiveness and safety have been debated 7.
Considerations for Treatment
When considering alternative treatment options, it is essential to take into account the specific type of infection, the patient's medical history, and the potential side effects of each medication.