what is the first time patient 28343 received a prescription for tramadol in 10/last year?
select prescriptions.startdate from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 28343 ) and prescriptions.drug = 'tramadol' and datetime(prescriptions.startdate,'start of year') = datetime(current_time,'start of year','-1 year') and strftime('%m',prescriptions.startdate) = '10' order by prescriptions.startdate asc limit 1