From the Guidelines
Terbinafine treatment for tinea capitis typically requires 2-4 weeks of therapy, depending on the patient's weight. The dosage for children is based on weight: less than 20 kg, 62.5 mg (or 625 mg, as the text is not clear on this point, but this seems to be an error) per day; 20-40 kg: 125 mg per day; and over 40 kg: 250 mg per day 1. For adults, the standard dose is 250 mg once daily. Complete resolution of symptoms may take longer than the treatment period, as hair regrowth occurs gradually after the fungal infection is eliminated.
Key Considerations
- Terbinafine is particularly effective against dermatophytes like Trichophyton species that commonly cause tinea capitis, as it works by inhibiting the enzyme squalene epoxidase, disrupting fungal cell membrane synthesis 1.
- Treatment should continue for the full prescribed duration even if symptoms improve earlier to ensure complete eradication of the infection.
- Regular liver function monitoring may be recommended during treatment, especially for extended courses, as terbinafine can occasionally affect liver enzymes.
Important Details
- The end point of treatment is mycological rather than clinical cure; therefore repeat mycology sampling is recommended until mycological clearance is achieved 1.
- Index cases due to T. tonsurans warrant screening of all family members and close contacts and treatment for those positive cases 1.
- Children receiving appropriate therapy should be allowed to attend school or nursery 1.
From the Research
Treatment Duration for Tinea Capitis with Terbinafine
- The treatment duration for tinea capitis with terbinafine varies, but most studies suggest a duration of 2-6 weeks 2, 3, 4, 5, 6.
- A study published in 2001 found that terbinafine was administered for 2-3 weeks, with an optional extra week of therapy if clinically indicated 2.
- Another study published in 2012 found that terbinafine was effective in treating tinea capitis with a cure rate of 96% after 2-3 weeks of treatment 3.
- A Cochrane review published in 2016 found that terbinafine for four weeks showed similar efficacy to griseofulvin for eight weeks in treating tinea capitis caused by Trichophyton species 4.
- A study published in 2009 found that treatment with terbinafine requires 6 weeks 5.
- A treatment update published in 2005 found that short-term terbinafine (2-3 weeks) was comparable in efficacy and safety to griseofulvin 6.
Factors Affecting Treatment Duration
- The causative organism may affect the treatment duration, with some studies suggesting that terbinafine is more effective against Trichophyton species than Microsporum species 4.
- The dose and duration of terbinafine may also affect the treatment outcome, with higher doses and longer durations potentially leading to better cure rates 4, 6.