We have, in the past, looked at mefloquine as having a benefit in that it is a once-a-week medication, and what we knew of its side effect profile compared favourably—before malarone was available—to the doxycycline, which has problems with sun sensitivity and people getting significant sunburns if they take it. When you looked at the side effect profiles known at the time, and the convenience....
There's an added protective factor because it's once a week. If you miss a pill of doxycycline one day and you are exposed to malaria, you can get malaria. If you miss your mefloquine pill and take it the next day, the likelihood of your getting malaria if you were bitten by a malaria-infected mosquito the day you forgot your pill is far lower, because the mefloquine is still in your system to protect you. That once-a-week protection factor was part of the consideration in recommending mefloquine.