Combinations comprising PDE 2 inhibitors such as 1-aryl-4-methyl-[1,2,4]triazolo-[4,3-A]]quinoxaline compounds and PDE 10 inhibitors for use in the treatment of neurological of metabolic disorders

The present invention relates to combinations of phosphodiesterase 2 (PDE2) inhibitors with inhibitors of phosphodiesterase 10 (PDE10). In particular, the invention relates to combinations of 1-aryl-4-methyl-[1,2,4]triazolo[4,3-a]-quinoxaline derivatives which have been found to inhibit phosphodiesterase 2 (PDE2), with inhibitors of phosphodiesterase 10 (PDE10). Particular PDE10 inhibitors are selected from the group of MP-10, PQ-10, TP-10, papaverine, and the compounds disclosed in WO 2011/051324 and in WO 2011/110545. The invention is also directed to pharmaceutical compositions comprising such combinations, to processes for preparing such compositions, to the use of PDE2 inhibitors, in particular of 1-aryl-4-methyl-[1,2,4]triazolo[4,3-a]-quinoxaline derivatives for the potentiation of said PDE10 inhibitors, and to the use of said PDE10 inhibitors for the potentiation of the effect of said PDE2 inhibitors, in particular, 1-aryl-4-methyl-[1,2,4]triazolo[4,3-a]-quinoxaline derivatives, and to the use of such combinations and compositions for the prevention and treatment of disorders in which PDE2 and PDE10 are involved, such as neurological and psychiatric disorders, and endocrinological or metabolic diseases.