Given the fact that "difficulty in urination" is a common side-effect of morphine
would imagine that the answer to SWIY quest is yes.
Also, they have a tendancy to dry the body out... which in general isn't good if a person doesn't take care to properly hydrate the body. Too little water in the system, would cause the kidneys to work harder. Surely someone can give a better/more detailed description about this process.
But in short, the answer to SWIY question is YES opiates
could affect the kidneys... But, I don't know that they really have to have much of a negative impact if a person were to take good care of their body and be aware about how their body works to offset the unhealthy things they do.