how many times has the carbamazepine xr been ordered for patient 23070 in this month?
select count(*) from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 23070 ) and prescriptions.drug = 'carbamazepine xr' and datetime(prescriptions.startdate,'start of month') = datetime(current_time,'start of month','-0 month')