urea + antifungal

The combination of a keratolytic agent and an antifungal is a sequential treatment regimen developed by Pierre Fabre Dermo Cosmetique for the management of onychomycosis (fungal nail infections). The primary component, RV4104A (marketed as Onyster), is a topical ointment containing 40% urea. It is classified as a Class I medical device and functions by selectively softening and degrading the infected nail plate through the denaturation of keratin and disruption of fungal attachments. This process, known as chemical avulsion, allows for the non-traumatic removal of diseased nail tissue. Following this initial keratolytic phase (typically lasting 3 weeks), a topical antifungal agent such as bifonazole or ciclopirox is applied to the exposed nail bed to eliminate the underlying fungal infection. This sequential approach is designed to enhance the penetration and efficacy of antifungal therapies in dermatophytic onychomycosis.

Brand names

Onyster

Other names

RV4104A + bifonazoleRV4104A + ciclopirox40% urea ointment