I worked in the export business out of Paris for several years - and in English speaking Africa (plus some trips to the likes of Togo/Cameroons/Senegal etc etc.)
We didnt follow the prescribed medication - we hit the system two days out with 5 tablets and then one a day through the trip away - and on return, another handful of 5.....
More importantly make sure that you are up on your tetanus and things like DTT and be careful of water - especially if the water out of a bottle is not aerated - I got nailed on that one care of Somalia (before the troubles) and after 20 years have only got a tri-glyceride liver function back into the ordinary range, not that it was life threatening and it could have been brought down faster (i.e.10 years) if I gave up drink - and the advice of the tropical doctor was "I wouldn't go for that course of actionif I was you"