If I'm out in the countryside for more than a week then I take Doxycycline. Side effects vary but I've never had any. Plus it's cheap as chips.
The main worry should be avoiding being bitten in the first place. Long sleeves are a must around dusk or when out in the Rice paddies and jungle. Trust me on this one. You do NOT want to get bitten and get Denge Fever! No amount of Tiger Balm is going to make you feel better with that one! Two weeks of agony *may* result in you having a crappy time.