Study on the usefulness of shampoo containing 0.75% miconazole nitrate for treatment of dandruff. A double-blind, comparative study

A double-blind, comparative study on the usefulness of shampoo containing 0.75% miconazole nitrate (MZS) for the treatment of dandruff was conducted at 8 institutions, using the shampoo vehicle (BSS) without the reagent as the control. The relationship between improvement in clinical symptoms, such as dandruff and itching, and the decrease in the count of Malassezia furfur, that is, mycological response, was also studied. Of a total of 134 subjects studied, 58 were shampooed with MZS, and 50 with BSS. One hundred thirty of these were included in a safety analysis, and 108 in an efficacy and usefulness analysis. MZS was evaluated as useful in 34 (58.6%) of the 58, and BSS in 19 (38.0%) of the 50 subjects, thus MZS was significantly more useful than BSS (p = 0.020). Dandruff improved in 42 (72.4%) of the 58 with MZS, and in 26 (52.0%) of the 50 subjects with BSS, MZS significantly reduced the dandruff and thus was more effective than BSS (p = 0.017). With regard to the relationship between the mycological response of M. furfur and the efficacy of shampooing against dandruff, the count of M. furfur decreased significantly in the subjects for whom the shampooing was evaluated as effective (p = 0.0001), whereas there was no significant difference between the baseline and posttreatment counts in those for whom the shampooing was evaluated as ineffective. Stratification of results of efficacy evaluation according to the baseline count revealed that MZS was more effective than BSS in subjects with relatively high counts of M. furfur (p = 0.038). No adverse reactions to either shampoo were observed in any of the 130 subjects. The above results suggested that MZS is effective against dandruff, and further, that the usefulness of this shampoo shows a relatively close correlation between the improvement in dandruff and decrease in the count of M. furfur.