Mefloquine is a controversial drug, a lot of people swear by it and it IS effective in preventing and treating certain kinds of Malaria. However, it does have some horrific side effects which do not effect everyone the same hence the difficulty with this drug. Unfortunately for me I had all of the side effects and I can literally say I was poisoned
so my advice is that you try and avoid it if you can.
That being said, perhaps in your case the other options might be even worse for you...