what medication was prescribed for patient 90917 in the same hospital visit after being diagnosed with pressure ulcer, low back since 64 months ago?
select t2.drug from ( select admissions.subject_id, diagnoses_icd.charttime, admissions.hadm_id from diagnoses_icd join admissions on diagnoses_icd.hadm_id = admissions.hadm_id where admissions.subject_id = 90917 and diagnoses_icd.icd9_code = ( select d_icd_diagnoses.icd9_code from d_icd_diagnoses where d_icd_diagnoses.short_title = 'pressure ulcer, low back' ) and datetime(diagnoses_icd.charttime) >= datetime(current_time,'-64 month') ) as t1 join ( select admissions.subject_id, prescriptions.drug, prescriptions.startdate, admissions.hadm_id from prescriptions join admissions on prescriptions.hadm_id = admissions.hadm_id where admissions.subject_id = 90917 and datetime(prescriptions.startdate) >= datetime(current_time,'-64 month') ) as t2 on t1.subject_id = t2.subject_id where t1.charttime < t2.startdate and t1.hadm_id = t2.hadm_id