Topical treatment of tinea pedis and fungal nail infections is a common avenue taken by patients and podiatrist alike. Topical applications of drugs have many advantages over systemic agents in terms of reduced side effects and costs. In the UK, the drugs available to treat onychomycosis topically are limited. Amorolfine 5% will be familiar to many podiatrists available as a generic or as the Loceryl and Curanail brands (Galderma UK Limited) being easily available to patients and practitioners through pharmacies and suppliers. Beyond that, there is little else. Tioconazole paint (27%) is available but evidence of its effectiveness falls well short of amorolfine. Moreover, amorolfine has a weekly application, tioconzole is daily affecting patients compliance and probably increasing the numbers of patients who fail to complete the full course of treatment.
The Terbinafine Molecule
A recent paper has been published which looks at a potential new avenue. Terbinafine is a tried and trusted anti-fungal product. Available in various formulations since the early 1990's, it has become a leading product for tinea pedis (as a cream, gel, spray or film forming solution) or for fungal nails as an oral agent. Now, scientists are working on its first licenced use for nail infection. This study have shown a good penetration into keratin using penetration enhancers such as urea. The next stag will be to try it on fungally infected nails with some clinical trials but hopefully it won't be too long before we can add a topical nail treatment into the terbinafine family.
Thatai, P. and B. Sapra (2017). "Transungual Gel of Terbinafine Hydrochloride for the Management of Onychomycosis: Formulation, Optimization, and Evaluation." AAPS PharmSciTech: 1-13.