What Are Sig Codes
Sig codes are the abbreviations used in the directions on a prescription. The "sig" comes from the Latin "signa," meaning "write" or "label." Pharmacy technicians must interpret these abbreviations accurately to process prescriptions correctly and ensure proper labeling.
Common Frequency Abbreviations
- QD - once daily
- BID - twice daily
- TID - three times daily
- QID - four times daily
- PRN - as needed
- Q4H, Q6H, Q8H - every 4, 6, or 8 hours
- HS - at bedtime
Common Route Abbreviations
- PO - by mouth
- SL - sublingual (under the tongue)
- TOP - topically
- INH - by inhalation
- IM - intramuscular
- IV - intravenous
- SC or SubQ - subcutaneous
Common Dosage Form Abbreviations
- TAB - tablet
- CAP - capsule
- SOL - solution
- SUSP - suspension
- SUPP - suppository
- GTT - drops
Putting It Together
A sig reading "1 TAB PO BID" means "take one tablet by mouth twice daily." Being able to quickly interpret these combinations is essential for both the exam and daily pharmacy work. Practice translating complete sig lines from abbreviations to plain English.
Error-Prone Abbreviations
Some abbreviations have been flagged as error-prone because they are easily misread. The Institute for Safe Medication Practices maintains a list of abbreviations that should be avoided in practice. Knowing which abbreviations are considered dangerous is a testable topic on the PTCE.
Study Approach
Create flashcards with the abbreviation on one side and the meaning on the other. Practice by writing out full prescription directions from abbreviated sig lines. This skill will serve you both on the exam and in your daily work as a technician.