| Item |
Information |
|
Drug Groups
|
approved; investigational |
|
Description
|
Terbinafine hydrochloride (Lamisil) is a synthetic allylamine antifungal. It is highly lipophilic in nature and tends to accumulate in skin, nails, and fatty tissues. Like other allylamines, terbinafine inhibits ergosterol synthesis by inhibiting the fungal squalene monooxygenase (squalene 2,3-epoxidase), an enzyme that is part of the fungal cell wall synthesis pathway. |
| Indication |
For the treatment of dermatophyte infections of the toenail or fingernail caused by susceptible fungi. Also for the treatment of tinea capitis (scalp ringworm) and tinea corporis (body ringworm) or tinea cruris (jock itch). |
| Pharmacology |
Terbinafine is an allylamine antifungal agent and acts by inhibiting squalene epoxidase, thus blocking the biosynthesis of ergosterol, an essential component of fungal cell membranes. In vitro, mammalian squalene monooxygenase (squalene 2,3-epoxidase) is only inhibited at higher (4000 fold) concentrations than is needed for inhibition of the dermatophyte enzyme. Depending on the concentration of the drug and the fungal species test in vitro, Terbinafine may be fungicidal. However, the clinical significance of in vitro data is unknown. |
| Affected Organisms |
|
| Biotransformation |
Hepatic |
| Absorption |
Readily absorbed from gastrointestinal tract. |
| Half Life |
36 hours |
| Protein Binding |
>99% |
| Elimination |
Prior to excretion, terbinafine is extensively metabolized. |
| References |
| • |
Darkes MJ, Scott LJ, Goa KL: Terbinafine: a review of its use in onychomycosis in adults. Am J Clin Dermatol. 2003;4(1):39-65.
[Pubmed]
|
| • |
Klobucnikova V, Kohut P, Leber R, Fuchsbichler S, Schweighofer N, Turnowsky F, Hapala I: Terbinafine resistance in a pleiotropic yeast mutant is caused by a single point mutation in the ERG1 gene. Biochem Biophys Res Commun. 2003 Sep 26;309(3):666-71.
[Pubmed]
|
| • |
Ryder NS: Terbinafine: mode of action and properties of the squalene epoxidase inhibition. Br J Dermatol. 1992 Feb;126 Suppl 39:2-7.
[Pubmed]
|
| • |
Birnbaum JE: Pharmacology of the allylamines. J Am Acad Dermatol. 1990 Oct;23(4 Pt 2):782-5.
[Pubmed]
|
| • |
McClellan KJ, Wiseman LR, Markham A: Terbinafine. An update of its use in superficial mycoses. Drugs. 1999 Jul;58(1):179-202.
[Pubmed]
|
| • |
Krishnan-Natesan S: Terbinafine: a pharmacological and clinical review. Expert Opin Pharmacother. 2009 Nov;10(16):2723-33.
[Pubmed]
|
| • |
Gianni C: Update on antifungal therapy with Terbinafine. G Ital Dermatol Venereol. 2010 Jun;145(3):415-23.
[Pubmed]
|
| • |
Korting HC, Kiencke P, Nelles S, Rychlik R: Comparable efficacy and safety of various topical formulations of terbinafine in tinea pedis irrespective of the treatment regimen: results of a meta-analysis. Am J Clin Dermatol. 2007;8(6):357-64.
[Pubmed]
|
|
| External Links |
|
|