My Son 21, Hospitalized A Year Ago With Drug Induced

My son 21, hospitalized a year ago with drug induced psychosis, diagnosed with schizophrenia. It's been a long yrs of healing. He has switched many meds but is currently down to 150 MG seroquil. Dr recently added med for high blood pressure and coles term due to weight gain and high readings. He hasn't had any more issues with psychosis for 9 months. He began having issues gagging a couple of months ago. He smokes, not a lot, but also smokes cannabis for anxiety. The gagging is getting worse. Hot and cold, shivering also. Doesn't feel sick but doesn't feel good. Today is especially bad. Dr doesn't seem concerned. Hasn't even looked in throat. Not sure what to do. He just threw up his lunch.