what was the name of the medicine that was prescribed to patient 52647 within the same hospital visit after receiving the packed cell transfusion procedure?
select t2.drug from ( select admissions.subject_id, procedures_icd.charttime, admissions.hadm_id from procedures_icd join admissions on procedures_icd.hadm_id = admissions.hadm_id where admissions.subject_id = 52647 and procedures_icd.icd9_code = ( select d_icd_procedures.icd9_code from d_icd_procedures where d_icd_procedures.short_title = 'packed cell transfusion' ) ) 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 = 52647 ) as t2 on t1.subject_id = t2.subject_id where t1.charttime < t2.startdate and t1.hadm_id = t2.hadm_id