instruction: what are the top three most commonly prescribed medicines since 1 year ago?
response: SELECT t1.drugname FROM (SELECT medication.drugname, DENSE_RANK() OVER (ORDER BY COUNT(*) DESC) AS c1 FROM medication WHERE DATETIME(medication.drugstarttime) >= DATETIME(CURRENT_TIME(), '-1 year') GROUP BY medication.drugname) AS t1 WHERE t1.c1 <= 3