Zoloft = Sertraline = Lustral (the brand name here) all the same thing.
Dosage *is* important, as is how you are started on it. When my doctor in Dubai prescribed it for me, he had me start on a half-dose, I think, over the course of 2 weeks or so, working up to the dose I was intended to take. He warned me that it would likely make me queasy at first, which is one reason why he had me get on it slowly; but he also told me that would go away, which it did.
Before I left Dubai, I asked my doctor to write up a letter for me, attesting to what medicines I was on, dosages and such. This proved very helpful when I did see a doctor here, as that helped with the continuation of all my meds. Zoloft, I learned, is called Sertaline or Lustral here.
I've since changed meds, but for a time, the Zoloft/Lustral helped quite a bit.