what was the drug that patient 22315 was prescribed for the last time using an td route since 145 months ago?
select prescriptions.drug from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 22315 ) and prescriptions.route = 'td' and datetime(prescriptions.startdate) >= datetime(current_time,'-145 month') order by prescriptions.startdate desc limit 1