instruction: how many of the patients diagnosed with icd9 code 4464 were treated with base drug?
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN diagnoses ON demographic.hadm_id = diagnoses.hadm_id INNER JOIN prescriptions ON demographic.hadm_id = prescriptions.hadm_id WHERE diagnoses.icd9_code = "4464" AND prescriptions.drug_type = "BASE"