q.h. (on prescription): This abbreviation signifies "every hour." When it appears on a prescription or in a doctor's hospital orders, it indicates that the medication should be administered hourly. It can also be written as qh, omitting the periods. The term derives from Latin, combining "quaque," meaning once, with "h" for hour. These Latin-derived abbreviations have long been utilized in prescriptions to denote how often medicines should be taken. Some other examples include: q.d. (qd or QD), which means once daily and comes from the Latin phrase "quaque die"; b.i.d. (bid or BID), indicating twice daily, from "bis in die"; t.i.d. (tid or TID), meaning three times daily, from "ter in die"; and q.i.d. (qid or QID), for four times daily, from "quater in die." When a medication must be taken every specified number of hours, it is denoted as "q_h," where "q" means "quaque" and "h" specifies the hours. For instance, "2 caps q4h" instructs the patient to take 2 capsules every 4 hours.
