It is usually out of your system quickly, like for the next dose. But if it helped you at all, you will start feeling that too.
As far as infections etc, the first three months you are on it--is the easiest to catch something.
Actema IV once a month (with pre loading for allergic reaction), Cymbalta x1 daily, Arava 20mg daily. Diagnosed with AS in 2004, suffered undiagnosed since 1982.