Mechanism of Action

The miconazole component of VUSION (miconazole nitrate, 15% zinc oxide, and 81.35% white petrolatum) is an antifungal agent. The mechanism of action of white petrolatum and zinc oxide for the adjunctive treatment of diaper dermatitis is unknown.

Pharmacodynamics

The human pharmacodynamics of Vusion (miconazole nitrate, 15% zinc oxide, and 81.35% white petrolatum) is unknown [see CLINICAL PHARMACOLOGY for fungal pharmacodynamics].

Pharmacokinetics

The topical absorption of miconazole from VUSION (miconazole nitrate, 15% zinc oxide, and 81.35% white petrolatum) was studied in immunocompetent male and female infants and children (n=17) with diaper dermatitis complicated by documented candidiasis (microscopic evidence of pseudohyphae and/or budding yeast) ranging in age from 1 month to 21 months. After multiple daily applications to the affected area at every diaper change (approximately 5-12 times per day) for 7 days, the plasma concentrations of miconazole were below the lower limit of quantitation (LOQ) of 0.5 ng/mL in 15 out of 17 (88%) subjects. In the other 2 remaining subjects, the plasma concentrations of miconazole were 0.57 and 0.58 ng/mL, respectively at a single timepoint (4 hours after the last application) on Day 7.

Microbiology

The miconazole nitrate component in this product has been shown to have in vitro activity against Candida albicans, an organism that is associated with diaper dermatitis. The activity of miconazole nitrate against C. albicans is based on the inhibition of the ergosterol biosynthesis in the cell membrane. The accumulation of ergosterol precursors and toxic peroxides results in cytolysis of the cell. In vitro minimal inhibitory concentration (MIC) test results for C. albicans isolates obtained from treatment failures in Clinical Study 1 (see Clinical Studies) does not appear to indicate that resistance to miconazole nitrate was the reason for treatment failure. The clinical significance of the in vitro activity of miconazole nitrate against C. albicans in the setting of diaper dermatitis is unclear.

Clinical Studies

Study 1 was a double-blind, multicenter study in which VUSION (miconazole nitrate, 15% zinc oxide, and 81.35% white petrolatum) was compared to the zinc oxide and white petrolatum combination treatment and included 236 infants and toddlers with diaper dermatitis, complicated by candidiasis as documented by KOH tests that demonstrated psuedohyphae and/or budding yeasts. Study medication was applied at every diaper change for 7 days.

The primary endpoint was “Overall Cure” and required that subjects be both clinically cured (total resolution of all signs and symptoms of infection) and microbiologically cured (eradication of candidiasis). Primary efficacy was assessed 1 week following the end of treatment, at Day 14.

Study results are shown in the following table.

Overall Cure at Day 14

Two additional studies provided supportive evidence of the clinical efficacy of VUSION (miconazole nitrate, 15% zinc oxide, and 81.35% white petrolatum) in infants and toddlers with diaper dermatitis, some of whom cultured positive for C. albicans. However, candidal infection was not documented in the culture-positive subjects, as microscopic testing (e.g. KOH) was not done. Therefore, the positive culture results may have reflected colonization rather than infection.

Last reviewed on RxList: 4/27/2010
This monograph has been modified to include the generic and brand name in many instances.