Which abbreviation is used to denote the instruction field on a prescription?

• A. sig.
• B. S
• C. s.o.s
• D. stat

Answer: (A)

The instruction field on a prescription is indicated by sig., which is short for signa. This Latin abbreviation marks where the prescriber writes the directions for the patient—how to take the medicine (dose, route, frequency, and duration). For example, the directions might read, “Take one tablet by mouth twice daily for 7 days” under sig.

Other terms like stat (immediately) or s.o.s (as needed) convey when or how urgently to take the medication, not the general patient directions. Therefore sig. is the label used to denote the instruction field.