singulaire for revved up immune system

[Guest guest]

my 32 month old asd son has a revved up immune system & strongly

increased amounts of mercury. we just got his 2nd heavy metal and

immune tests back. our dan doctor prescribed singulaire for his immune

system but it looks like it is loaded with illegals. these are 4mg

chewables which include aspartame, cherry flavor, magnesium stearate,

croscarmellose sodium, mannitol, microcrystalline cellulose,

hydroxypropyl cellulose, red ferric oxide, montelukast sodium. i am

sure there is several ingreds which he should avoid. is this legal and

if not, is their another option for singulaire?