I think if you're lowering your N dose and starting L then its not so bad, but I'm sure being on both together isn't wise, due to seretonin levels.

The best way to check for sure is to use the drug interaction checker on www.drugs.com Type both in then search for interactions and it will tell you whether there are mild/moderate/severe issues with taking both at once. Of course this comes with a disclaimer and if you aren't sure you should get your doctor to check, but it'll give you an idea on what problems may arise with taking both at once at normal doses (ie not coming down off one while introducing the other)

x Kate