  On the basis of the equivalence of the energy balance deacription at micro-
and macro-level we propose a quantum generalization of the viscous friction law
for a macroscopic Langevin equation describing thermal fluctuations without the
zero point contribution. This equation recovers the classical case in the limit
h -> 0. In particular it satisfies the quantum regression theorem and resolves
several anomalies appearing in the quantum extension of the fluctuation
dissipation theorem.
