On a prescription, "qd" (or "q.d.") signifies taking a medication once daily, derived from Latin. Sometimes, it's written in capital letters without periods as "QD." Regardless of the format, it's part of a set of traditional Latin abbreviations used to indicate how frequently medications should be administered.Other common abbreviations include:- "b.i.d." (or "bid" or "BID"), meaning twice daily, comes from the Latin term "bis in die."- "t.i.d." (or "tid" or "TID") refers to taking a medication three times daily and stands for "ter in die" in Latin.- "q.i.d." (or "qid" or "QID") indicates taking something four times daily, derived from "quater in die" in Latin.When a medication is prescribed to be taken at specific hourly intervals, it is denoted as "q_h," where "q" stands for "quaque" (meaning every), and "h" specifies the number of hours. For instance, "2 caps q4h" means "Take 2 capsules every 4 hours."
