Do Not use Meflaquin(spelling?).
That is the one that you take once a week in place of Paludrin/Nivaquin combination. Meflaquin creates hallucinations, (from personal experience) induces depression and suicidal tendancies. Rumour has it that long term use of Meflaquin will damage your eyesight and colour differentiation as well damaging your liver and kidneys. If the CAA find out you have been taking it they will suspend your Class 1 medical.
If you are only going in and out on an irregular basis and not staying long (a couple of days for example), it probably isnt worth taking a course of drugs, BUT, and an important but, if you start to feel 'fluey within a month of returning, go straight to your GP and tell him where you have been and that you must be checked out for malaria.