Client-owned dogs with atopic dermatitis were used in this study to determine the safety and efficacy of cyclosporine in the treatment of atopic dermatitis. In the first phase of the study, dogs were treated with either cyclosporine (3.3 to 6.6 mg/kg PO once a day) or placebo for 4 weeks. In phase 2, all dogs were given cyclosporine. Capsules were given at least 2 hours before or after feeding. An approved flea adulticide was applied to all dogs at the time of study. Other medical treatments were allowed only for conditions unrelated to dermatitis. The canine atopic dermatitis extent and severity index (CADESI) was used to evaluate the dogs at the beginning of the study and after 4 weeks. Owners were also asked to evaluate the severity of pruritus. Data were evaluated for 107 treated dogs and 111 control dogs. Those in the cyclosporine-treated group had significantly lower CADESI scores at the end of treatment. Owners also felt that pruritus was decreased. During phase 2, the cyclosporine was reduced after 12 weeks to every-other-day administration for 36% of the dogs and twice weekly for 22% of the dogs.
COMMENTARY: This relatively large study of 268 North American dogs treated with cyclosporine for atopic dermatitis confirmed not only the efficacy of the drug for this condition but also its safety over a several-month period. Side effects were mild (primarily transient gastrointestinal signs), incidence of otitis externa decreased, and effective control of dermatitis could be maintained with a tapering dose in most cases. Without doubt, cyclosporine provides a much-needed alternative to steroid therapy for control of atopic dermatitis.
Clinical trial evaluating the efficacy and safety of cyclosporine in dogs with atopic dermatitis. Steffan J, Parks C, Seewald S, et al. JAVMA 226:1855-1863, 2005.