My son is 14 yaers old he has eplicey very bad he is on constent medication for it but he has bad breath?

he has alot of needs his breath smells so bad sometimes i brush his teath sometimes3 times a day and the care staff at school have said the same thay dont know what it could be eather i have 3 outhe foster kids aged 6,8.12 as well thay wake up with slight bad breath but it goes

This may involve a trip to the dentist to see what is going on with the teeth. Some epilepsy medicines do things to the teeth and gums. There may also be an infection there causing this.
It may involve a time of talking to your pharmacist. Some medicines can cause bad breath.
Once the cause is established, then a solution should not be far behind!

Have him brush his tongue and rinse with mouth wash.

ask your doctor it could be a side effect of some medicine or he may have an infection of some sort.

the bad breathe could be a side affect of one of his medications, if its that bad i would contact the doctors office to get an opinion on which med it could be, and what could possibly be done, if anything.
another thing, when's the last time he went to the dentist to have his teeth cleaned