Sig codes and pharmacy abbreviations
The Sig is the directions part of a prescription, written in Latin shorthand. Type one below to see how it reads on the label, then use the reference to learn the codes for the PTCE.
Try one
On the label
Take 2 capsules by mouth three times daily for 10 days.
A study aid: the pharmacist checks every label before it goes out.
Sig code reference
Periods are optional: b.i.d. and bid mean the same thing.
How often
- daily
- Once a day (write "daily"; QD is on the Do Not Use list)
- b.i.d.
- Twice daily
- t.i.d.
- Three times daily
- q.i.d.
- Four times daily
- q4h, q6h, q8h, q12h
- Every 4, 6, 8 or 12 hours
- q.a.m. / q.p.m.
- Every morning / every evening
- q.wk.
- Once a week
- p.r.n.
- As needed
- stat
- Immediately
When and how long
- a.c.
- Before meals
- p.c.
- After meals
- h.s.
- At bedtime
- x10d
- For 10 days
- ut dict
- As directed
- ad lib
- Freely, as desired
- n/v, SOB, CP
- Nausea and vomiting, shortness of breath, chest pain (reasons after p.r.n.)
Routes
- p.o.
- By mouth
- SL
- Under the tongue (sublingual)
- buccal
- Between the cheek and gum
- PR / PV
- Rectally / vaginally
- top
- To the skin (topical)
- inh
- By inhalation
- IM / IV
- Into the muscle / into a vein
- SUBQ
- Under the skin (subcutaneous)
- NG
- Through a tube from the nose to the stomach
Eyes and ears
- OD / OS / OU
- Right eye / left eye / both eyes
- AD / AS / AU
- Right ear / left ear / both ears
Amounts and symbols
- tab / cap
- Tablet / capsule
- gtt
- Drop(s)
- tsp / tbsp
- Teaspoon (5 mL) / tablespoon (15 mL)
- i, ii, iii
- 1, 2, 3
- ss
- One-half
- c with a line over it
- With
- s with a line over it
- Without
- aa
- Of each
- qs ad
- Add enough to make
Do not use (write it out instead)
- U
- units
- IU
- international units
- QD
- daily
- QOD
- every other day
- cc
- mL
- SC, SQ, sub q
- SUBQ or subcutaneously
- MS, MSO4, MgSO4
- the full drug name
- Trailing zero (5.0 mg)
- 5 mg
- No leading zero (.5 mg)
- 0.5 mg
How to read a Sig
Most Sigs follow the same order: how much, what form, which route, how often, and sometimes how long or why. “1 tab po bid x10d” is 1 tablet, by mouth, twice daily, for 10 days.
The label starts with a verb that fits the form: take a tablet, instill a drop, inhale a puff, apply a cream, insert a suppository, inject insulin.
Learn Sig codes in short lessons
Gutta's lessons cover Sig codes, routes, Roman numerals and error-prone abbreviations, with practice questions after each one.
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