instruction: a month before when was the last time that patient 27703 was prescribed medication via the tp route?
response: SELECT prescriptions.startdate FROM prescriptions WHERE prescriptions.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 27703) AND prescriptions.route = 'tp' AND DATETIME(prescriptions.startdate, 'start of month') = DATETIME(CURRENT_TIME(), 'start of month', '-1 month') ORDER BY prescriptions.startdate DESC LIMIT 1