when was the last time since 118 months ago that patient 14987 was prescribed aspirin ec and heparin sodium at the same time?
select t1.startdate from ( select admissions.subject_id, prescriptions.startdate from prescriptions join admissions on prescriptions.hadm_id = admissions.hadm_id where prescriptions.drug = 'aspirin ec' and admissions.subject_id = 14987 and datetime(prescriptions.startdate) >= datetime(current_time,'-118 month') ) as t1 join ( select admissions.subject_id, prescriptions.startdate from prescriptions join admissions on prescriptions.hadm_id = admissions.hadm_id where prescriptions.drug = 'heparin sodium' and admissions.subject_id = 14987 and datetime(prescriptions.startdate) >= datetime(current_time,'-118 month') ) as t2 on t1.subject_id = t2.subject_id where datetime(t1.startdate) = datetime(t2.startdate) order by t1.startdate desc limit 1