Dystrophic psoriatic fingernails treated with 1% 5-fluorouracil in a nail penetration-enhancing vehicle: A double-blind study

Background: Topically applied nail therapeutics need to permeate the nail p late to reach the nail bed or nail matrix and exert their potential benefic ial effect at these locations to obtain a therapeutic benefit. So far only topically applied 5-fluorouracil on affected nails of psoriatic patients ha s been shown to produce a notable clearance. Vehicle formulations enhancing nail permeation processes are thought to increase the concentration of the active agent and therefore therapeutic efficacy, possibly enabling the use of a low concentration of the active agent thereby lowering the incidence of adverse effects. Objective: This study was designed to verify whether a recently developed nail penetration enhancer in a lotion formulation, Belan yx(R) (urea, propylene glycol), improves the efficacy of a low concentratio n of 5-fluorouracil (1%) in psoriatic fingernail lesions. Methods: In a ran domised, double-blind, left-right study the efficacy of 1% 5-fluorouracil i n the Belanyx vehicle was compared to the vehicle preparation Belanyx in dy strophic fingernails of 57 psoriatic patients. Both preparations were appli ed in a once daily regimen for 12 weeks. Responses and adverse effects of o ne selected target nail were recorded at screening, at baseline and at week s 2, 4, 8 and 12 of treatment with a final assessment at week 16: 4 weeks a fter the end of treatment. As parameter of efficacy was chosen the total na il area severity (NAS) score, consisting of the separate parameters nail pi tting area, number of nail pits, subungual keratosis, onycholysis, oil spot s and the various scores of overall improvement. Results: The efficacy of 1 % 5-fluorouracil in lotion and that of the vehicle in suppressing the param eters of dystrophy were shown to be similar at the end of treatment (p = 0. 063) or follow-up (p = 0.130). Both preparations produced statistically sig nificant improvements (p less than or equal to 0.05) for almost all assesse d parameters after 12 weeks of treatment and after the 4 weeks of follow-up . For Belanyx lotion this applied to the nail pitting area, the number of n ail pits, subungual keratosis, onycholysis and oil spots. The investigators ' and patients' opinion of overall improvement of severity as well as the t otal NAS score of one target nail likewise showed a statistically significa nt improvement at the end of treatment and at the end of the observation pe riod (p less than or equal to 0.05). With the 1% 5-fluorouracil lotion the same statistically significant improvements were obtained in all of the ass essed symptoms with the exception of the number of pits and onycholysis at week 12 and week 16. Possible treatment-related adverse effects were establ ished in 6 patients showing inflammation and infection (3 patients) or disc oloration (5 patients); 3 patients on 5-fluorouracil lotion showed onycholy sis. Conclusion: Addition of 1% 5-fluorouracil to the nail permeation enhan cer Belanyx does not increase the efficacy of the active agent in psoriatic nail dystrophy of this study population. The obtained results also suggest that Belanyx lotion can be used in this indication since it has shown a fa vourable efficacy-safety ratio. Copyright (C) 2000 S. Karger AG, Basel.