Larium is a weekly tablet and if you have never used it before I would advise at least a 3 week trial before you go on holiday as it can have bizarre side effects such as bad dreams.
Side effects may include: nausea, diarrhoea, dizziness, abdominal pain, rashes, skin itch, headache, dizziness, convulsions, sleep disturbances (insomnia, vivid dreams) and psychotic reactions such as depression.
Anyone with a history of low mood/depression should not take larium.
Last year in Zambia I opted for Malarone, they are more expensive but I had no side effects whatsoever.
Hope this helps.
Janice