What does od stand for in dosing intervals?

• A. Once daily
• B. Twice daily
• C. Every hour
• D. Before meals

Answer: (A)

In dosing intervals, od means once daily, i.e., one dose every 24 hours. This shorthand communicates that only a single administration is needed per day, which is different from dosing that is twice daily (every 12 hours) or hourly (every hour) or timing tied to meals (before meals). Using od helps simplify schedules and support adherence. Note that in other contexts od can be confused with unrelated meanings (like an eye designation), so some clinicians prefer writing “every 24 hours” to avoid misinterpretation.