This invention relates to adenosine kinase inhibitors and to nucleoside analogs, C-4' modified pyrrolo�2,3-d!pyrimidine and pyrazolo�3,4-d!pyrimidine nucleoside analogs having activity as adenosine kinase inhibitors. The invention relates to nucleoside analogs of this kind, having zero substitutions or two substitutions at the C-4' position of the furanose (sugar) moiety. The invention also relates to the preparation and use of these adenosine kinase inhibitors in the treatment of cardiovascular, and cerebrovascular diseases, inflammation and other diseases which can be regulated by increasing the local concentration of adenosine.