instruction: what was the amount of normocarb prescribed to patient 28484,, in total, until 63 months ago?
response: SELECT SUM(prescriptions.dose_val_rx) FROM prescriptions WHERE prescriptions.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 28484) AND prescriptions.drug = 'normocarb' AND DATETIME(prescriptions.startdate) <= DATETIME(CURRENT_TIME(), '-63 month')