what was the name of the drug prescription that patient 17608 was first prescribed since 138 months ago?
select prescriptions.drug from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 17608 ) and datetime(prescriptions.startdate) >= datetime(current_time,'-138 month') order by prescriptions.startdate asc limit 1