The present invention comprises the substituted 2-aminoalkylthiobenzimidazoles of formula I wherein R1-R5 and R11-R16 are hereinafter defined. These compounds, their derivatives and the pharmaceutically acceptable salts thereof are useful in the reduction of elevated blood sugar levels and are therefore useful in the treatment of hyperglycemia, diabetes, atherosclerosis and other blood sugar disorders. These compounds are particularly suitable in the treatment of type-2 diabetes.