My Son Has Been On Methadone For 18 Days Started

My son has been on methadone for 18 days started at 30 for 3 40 for 3 50 for 3 60 for 3 now on 70 msg he appears to always be sluggish slurry in a stupor and worse than when he was on opiates he is 18 and very much in denial of getting any other kind of help we are going to tell him that we are not going to participate in this program anymore as I feel it is making him worse. Will he be ok and will he have bad withdrawals
lau