Niece going to Ecuador ; question about anti-malarial drug,Larium?

My niece is going to Ecuador in the fall for 10 weeks,and she is supposed to take Larium weekly to prevent malaria.The drug,however,has many side effects and I was wondering if anyone has taken it and had a bad reaction. Also,we have read that a person can take doxycycline instead. What can you tell me about Larium and should she take it or try for doxycycline?