Provided are combinations of inhibitors of dipeptidyl peptidase IV (DP IV) and of enzymes having the same substrate specificity (DP IV-analogous enzymatic activity) and inhibitors of alanyl aminopeptidase (aminopeptidase N, APN) and of enzymes having the same substrate specificity (APN-analogous enzymatic activity) and use of the same to obtain a more than additive to superadditive inhibition for the treatment of arteriosclerosis, for the treatment of allergic reactions of the type I according to the Gell and Coombs classification and for the treatment of dermatological diseases with follicular and epidermal hyperkeratoses and an enhanced proliferation of keratinocytes.