and what was the last time patient 2957 was prescribed medication using the iv drip route since 120 months ago?
select prescriptions.startdate from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 2957 ) and prescriptions.route = 'iv drip' and datetime(prescriptions.startdate) >= datetime(current_time,'-120 month') order by prescriptions.startdate desc limit 1