Imidazole and benzimidazole derivatives useful as histamine H3 antagonists

Disclosed are compounds of the formula or a pharmaceutically acceptable salt or solvate thereof, wherein: n is 2-5; R is R3-aryl, R3-heteroaryl, R3-cycloalkyl, R3-heterocycloalkyl, alkyl, haloalkyl, -OR4, -SR4 or -S(O)1-2R5; R1 and R2 are H or optionally substituted phenyl or optionally substituted and X is -O- or -S-; or R1 and R2, together with the carbon atoms to which they are attached form optionally substituted and X is -O-, -S- or -NR7-; Z is and the remaining variables are as defined in the specification; also disclosed are pharmaceutical compositions comprising the compounds of formula I; also disclosed are methods of treating allergy, allergy-induced airway responses, congestion, obesity and metabolic syndrome using the compounds of Formula I, as well as combinations with other drugs useful for treating those diseases.