Which abbreviation means at bedtime?

• A. P.O.
• B. STAT
• C. H.S.
• D. QID

Answer: (C)

Timing of medication administration is shown by common abbreviations; the one that means at bedtime is H.S., which stands for hora somni and indicates the dose should be taken at night before sleep. This timing helps align the drug’s effect with the patient’s sleep period, which is especially important for sedatives or sleep aids. By contrast, P.O. indicates the route by mouth but not the time; STAT means take it immediately; and QID means four times daily. So the bedtime indication is the reason this option is the correct choice.