what was the name of a drug patient 12726 was last prescribed in this month?
select prescriptions.drug from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 12726 ) and datetime(prescriptions.startdate,'start of month') = datetime(current_time,'start of month','-0 month') order by prescriptions.startdate desc limit 1