This paper introduces a shifted composition rule to adapt coupling arguments to the Kullback-Leibler (KL) divergence.The framework combines local error analysis and Girsanov's theorem to yield tight bounds and KL divergence guarantees.It is applicable in cases of strongly log-concave, weakly log-concave, or log-Sobolev target distributions.The results include KL guarantees for the randomized midpoint discretization of the Langevin diffusion.