The abbreviation 'h.s' indicates which instruction?

• A. With meals
• B. Before meals
• C. At bedtime
• D. Every two hours

Answer: (C)

Understanding dosing times often relies on Latin abbreviations used on prescriptions. The abbreviation h.s stands for hora somni, meaning “at the hour of sleep” or simply at bedtime. This tells you the medication should be taken when the patient is going to sleep, not with meals, not before meals, and not on a frequent every-two-hours schedule. It’s commonly used for drugs that are best taken at night or that help with sleep, such as certain sedatives or nighttime pain medications. In modern practice, clinicians may avoid these abbreviations due to potential misinterpretation, but their intended meaning remains taking the dose at bedtime.