Low sodium at 122. Edema ( last year)

My mother had a fall few days ago on 10 march  due to low balance n tiredness. Also exhibited confusion n memory issues two three days after that. She was undergoing treatment for brain inflammation-antiseizure medicines,along with  diuretic, immunosuppressents, quetepine etc Did blood tests n found sodium at 122 on 22 March. Did consultation n started with two medicines Tolvapton15. One per day for 5days Sodamint 2000(3-3-3) for three days. We will be testing sodium levels after three days of medication. She appear normal except for sleepiness n difficulty in getting up.. urination is slow n reduced a bit before starting salt tablet itself. How often we should repeat test of sodium levels in blood considering she is also on diuretic due to previous history of pulmonary edema ( last year)