The prophylactic effect does not begin immediately upon starting the drugs, so people temporarily visiting malaria-endemic areas usually begin taking the drugs one to two weeks before arriving and must continue taking them for 4 weeks after leaving (with the exception of atovaquone proguanil that only needs be started 2 days prior and continued for 7 days afterwards).
Athari ya kuzuia ugonjwa haianzi mara moja baada ya kuanza kwa dawa, kwa hivyo watu wanaotembelea kwa muda maeneo yenye malaria kwa kawaida huanza kutumia dawa wiki moja hadi mbili kabla ya kufika na lazima waendelee kuzitumia kwa wiki 4 baada ya kuondoka (isipokuwa atovaquone proguanil pekee). mahitaji yaanzishwe siku 2 kabla na kuendelea kwa siku 7 baadaye).