I'm not a professional so this comes from my experience...

Your doctor may suggest switching to a different med in the same class. If that is the case, then usually they go about doing so by just abruptly stopping your Zoloft and starting you with another SSRI.

If, though, he thinks its best to use another class, then sometimes they cross taper; where they gradually decrease your Zoloft and at the same time start you on a new med. That's what happened when I had no luck with SSRIs and my doc tried me on NaSSA, which I'm taking now...

hope this helps!