If you want answer to these kinds of questions, I suggest you go to Erowid. Here is the page for Mefloquine https://www.erowid.org/experiences/subs/exp_Pharms_Mefloquin...

As you see, not too much data but it is still something. From the reports, it doesn't look like there is recreative potential. It doesn't hurt to look but the general idea is that if a strong psychoactive is not heavily controlled/illegal, the effects are usually nothing but unpleasant.