I was on Mephloquine when I was an UN Military Observer down in the Sudan last year. The only thing that affected me from the Mephloquine was having wild vivid dreams. Other than that, no problems.
You would not want to get malaria. I saw a couple of guys who did and one was a 250 pound Rugby playing Fijian who was an UNMO in my teamsite. He was reduced to a shivering mess with no energy whatsoever who had to be medivaced to the UN hospital at JUBA by MI-8 helicopter.