what was the citalopram hydrobromide dose that patient 55700 was first prescribed in 03/last year?
select prescriptions.dose_val_rx from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 55700 ) and prescriptions.drug = 'citalopram hydrobromide' and datetime(prescriptions.startdate,'start of year') = datetime(current_time,'start of year','-1 year') and strftime('%m',prescriptions.startdate) = '03' order by prescriptions.startdate asc limit 1