instruction: what was the last drug until 52 months ago that patient 2700 was prescribed via the ou route?
response: SELECT prescriptions.drug FROM prescriptions WHERE prescriptions.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 2700) AND prescriptions.route = 'ou' AND DATETIME(prescriptions.startdate) <= DATETIME(CURRENT_TIME(), '-52 month') ORDER BY prescriptions.startdate DESC LIMIT 1