Hello, If I were treating you as my client, I would need to know all reasons for the nausea, appetite loss and tremors before I could treat. One of the problems in medicine today is treating symptoms and not the problem. Nausea, such as from withdrawal, can be treated by ginger root made into a tea. Ginger ale has no real ginger in it. The tea can be consumed warm or iced, whichever makes your son feel better. Have him take slow sips, do not fill stomach very full of anything, sleep propped up and hydrated with popsicles or any fluids you can keep down. If these reactions have lasted four weeks I highly advise you take him to the appropriate doctor for a second opinion on how to give him medical relief. Once and if he provides you with a secondary diagnosis please write back and I will see if I can help you more specifically. Withdrawals that are sever enough to last 4 weeks at the severity you are speaking of is nothing shy of torture and he needs immediate relief. There are prescription medication for nausea. Any type of vitamin relief takes time (and you need immediate relief) should be followed by a dietitian therapist and implemented with lifestyle changes with support, education and guidance. There are specific vitamin routines,that given under supervision, can support mental, emotional or other specific diagnostic issues. For example, melatonin helps with sleep problems,but without a complete assessment and evaluation I cannot recommend that. You may write me again after he is seen by his physician and is given a specific diagnosis and medical recommendations with nutrition orders and I will then guide you on those. I feel your son needs immediate relief. Please take him in for a second opinion and try ginger root, try to keep him hydrated. I just can t recommend anything without a complete assessment and in his case he needs to be seen immediately by a physician. Regards, Kathryn Shattler MS, RDN You may follow up with me at any time