when was the first time when patient 31482 was prescribed phenylephrine hcl and albumin 5% (25g / 500ml) at the same time in this month?
select t1.startdate from ( select admissions.subject_id, prescriptions.startdate from prescriptions join admissions on prescriptions.hadm_id = admissions.hadm_id where prescriptions.drug = 'phenylephrine hcl' and admissions.subject_id = 31482 and datetime(prescriptions.startdate,'start of month') = datetime(current_time,'start of month','-0 month') ) as t1 join ( select admissions.subject_id, prescriptions.startdate from prescriptions join admissions on prescriptions.hadm_id = admissions.hadm_id where prescriptions.drug = 'albumin 5% (25g / 500ml)' and admissions.subject_id = 31482 and datetime(prescriptions.startdate,'start of month') = datetime(current_time,'start of month','-0 month') ) as t2 on t1.subject_id = t2.subject_id where datetime(t1.startdate) = datetime(t2.startdate) order by t1.startdate asc limit 1