what was the drug that in 04/this year patient 72198 was prescribed via the ih route for the last time?
select prescriptions.drug from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 72198 ) and prescriptions.route = 'ih' and datetime(prescriptions.startdate,'start of year') = datetime(current_time,'start of year','-0 year') and strftime('%m',prescriptions.startdate) = '04' order by prescriptions.startdate desc limit 1