instruction: what are the number of patients who received calcium channel blocker during the same hospital encounter after having received antibacterials until 2104?
response: SELECT COUNT(DISTINCT t1.uniquepid) FROM (SELECT patient.uniquepid, treatment.treatmenttime, patient.patienthealthsystemstayid FROM treatment JOIN patient ON treatment.patientunitstayid = patient.patientunitstayid WHERE treatment.treatmentname = 'antibacterials' AND STRFTIME('%y', treatment.treatmenttime) <= '2104') AS t1 JOIN (SELECT patient.uniquepid, treatment.treatmenttime, patient.patienthealthsystemstayid FROM treatment JOIN patient ON treatment.patientunitstayid = patient.patientunitstayid WHERE treatment.treatmentname = 'calcium channel blocker' AND STRFTIME('%y', treatment.treatmenttime) <= '2104') AS t2 WHERE t1.treatmenttime < t2.treatmenttime AND t1.patienthealthsystemstayid = t2.patienthealthsystemstayid