In this paper, we analyze the informational properties of time series of slip velocity generated by the Langevin equation of friction in two different frictional regimes: viscous and Coulombian. Representing the generated time series in the Fisher-Shannon plane (where the coordinate axes are the Fisher Information Measure and the Shannon entropy power), the two different frictional regimes are well discriminated. In particular, the viscous regime is characterized by smaller Shannon entropy than the Coulombian one. Furthermore, also the Fisher Information Measure of the slip velocity smoothed by average filter depends on the frictional mechanism, being larger for the viscous regime.