tell me the name of the medication that patient 14397 was last prescribed via the oral route during their last hospital visit?
select prescriptions.drug from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 14397 and admissions.dischtime is not null order by admissions.admittime desc limit 1 ) and prescriptions.route = 'oral' order by prescriptions.startdate desc limit 1