when was the last time that patient 2425 was prescribed medication until 11/2104 via right eye route?
select prescriptions.startdate from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 2425 ) and prescriptions.route = 'right eye' and strftime('%y-%m',prescriptions.startdate) <= '2104-11' order by prescriptions.startdate desc limit 1