Which abbreviation corresponds to the meaning 'At bedtime'?

• A. Gtt(s)
• B. Qhs
• C. Ns
• D. Po

Answer: (B)

When reading medication orders, timing is conveyed with specific abbreviations. At bedtime is expressed as QHS, which stands for quaque hora somni and means to take the dose every night at the hour of sleep. This is the best choice because it directly indicates when to dose. The other terms don’t denote timing: Gtt(s) means drops (a form of administration, not time); Ns isn’t a standard timing abbreviation; Po means by mouth (the route), not when to take the medication.