what were the four most frequent drugs that were prescribed in the same hospital visit to the patients with age 40s after having been diagnosed with iatrogenc hypotnsion nec, in the previous year?
select t3.drug from ( select t2.drug, dense_rank() over ( order by count(*) desc ) as c1 from ( select admissions.subject_id, diagnoses_icd.charttime, admissions.hadm_id from diagnoses_icd join admissions on diagnoses_icd.hadm_id = admissions.hadm_id where diagnoses_icd.icd9_code = ( select d_icd_diagnoses.icd9_code from d_icd_diagnoses where d_icd_diagnoses.short_title = 'iatrogenc hypotnsion nec' ) and datetime(diagnoses_icd.charttime,'start of year') = datetime(current_time,'start of year','-1 year') ) as t1 join ( select admissions.subject_id, prescriptions.drug, prescriptions.startdate, admissions.hadm_id from prescriptions join admissions on prescriptions.hadm_id = admissions.hadm_id where admissions.age between 40 and 49 and datetime(prescriptions.startdate,'start of year') = datetime(current_time,'start of year','-1 year') ) as t2 on t1.subject_id = t2.subject_id where t1.charttime < t2.startdate and t1.hadm_id = t2.hadm_id group by t2.drug ) as t3 where t3.c1 <= 4