Terbinafine

Allylamine antimycotic.

Inhibition of squalene epoxidase (see SQLE gene below), accumulation of fungicidally active squalene. Excretion: 71% renal, 22% fecal.

Acquired terbinafine resistance has recently occurred in several countries. It arises from a missense mutation, a point mutation in the SQLE gene, which leads to the amino acid substitutions Phe39Leu and Leu 303Phe in the SQLE protein. This is exactly the target of terbinafine. Cases of terbinafine-resistant T. indotineae (Tr. mentagrophytes ITS genotype VIII) with clinical failure have been reported mainly in Germany and Iran (Tamimi P et al. 2024).

Infections with dermatophytes (tinea capitis, tinea corporis, onychomycosis). Also effective in sporotrichosis ( off-label use). The efficacy in sporotrichosis was demonstrated in 2 studies. Also in mixed infections with Candida species (mycelial form) and Scopularopsis.

Allergic reactions, rarely Quincke's edema and drug-induced Lyell syndrome, AGEP, disorders of the sense of taste, BB changes (neutropenia, thrombocytopenia), gastrointestinal disorders, arthralgias, myalgias, rarely liver cell damage up to fatal liver cell necrosis.

Deterioration of psoriasis.

Notice! Due to the side effects, systemic use in Sweden has been limited to therapy-resistant onychomycoses!

Topical: e.g. Lamisil Pedisan cream, DermGel and spray.

Systemic: e.g. Lamisil, Terbinafine

In Switzerland and Austria Terbinafine is approved for oral application in children, in Germany however not yet ( off-label use). A careful documentation and education of parents about the off-label use and the effect of Terbinafine in studies should be carried out. The dosage recommendation is: Children with 10-20 kg bw: 62.5 mg/day; 21-40 kg bw: 125 mg/day; > 40 kg bw: 250 mg/day. 2 weeks of therapy are normally sufficient.

In a randomized double-blind study it could be shown that a therapy with Terbinafine cream 1% over 7 days (once/day) is sufficient to cure a Tinea pedis interdigitalis.

1. Seebacher C et al (2006) Tinea capitis. J Dtsch Dermatol Ges 4: 1085-1091
2. Seebacher C et al (2007) Tinea of the free skin. J Dtsch Dermatol Ges 11: 921-926
3. Tamimi P et al. (2024) Terbinafine-resistant T. indotineae due to F397L/L393S or F397L/L393F mutation among corticoid-related tinea incognita patients. J Dtsch Dermatol Ges 22:922-934.
4. Uhrlass S et al. (2022) Trichophyton indotineae-An Emerging Pathogen Causing Recalcitrant Dermatophytoses in India and Worldwide-A Multidimensional Perspective. J Fungi (Basel) 8:757.
5. Wilmer A et al. (1998) Systemic terbinafine treatment of dermatophytoses in children. Mycoses 41: 54-57