Symptoms of overmedicating

My son is a recovering addict from Opiates and was diagnosed Hypothyroidism while in rehab. He had been given Lithium by Psychiatrist prior to that but was taken off during admission & eval. He has monitored & tested again by blood work but dosage same. he is currently showing signs of hyperness, face breaking out, irritability, insomnia, loss of weight & just can't stay still. These are signs of over medicating according to articles. Due to insurance, had to get a generic prescription from Walmart while waiting for mailorder prescription. Read where some generics can be a problem. Anyone else experience this?