Overview
This lecture covers essential pharmacy sig codes, their categories, units of measure, Roman numerals, and provides prescription examples to help understand their use in medication orders.
Introduction to Sig Codes
- Sig codes are Latin-based prescription abbreviations used by medical professionals.
- "Sig" comes from "signature," meaning "let it be labeled."
- Understanding sig codes is crucial for accurately entering and communicating prescription instructions.
Categories of Sig Codes
1. Time of Day & Frequency
- q = every (e.g., qh = every hour, qam = every morning)
- qd = once daily, qod = every other day, qwk/qw = every week, qmo = every month
- q6h = every six hours, bid = twice a day, tid = three times a day, qid = four times a day
- prn = as needed
2. Extra Detail Codes
- ac = before meals, pc = after meals, cf = with food, hs = at bedtime, stat = immediately, ud = as directed
- wa = while awake, tat/uat = until all are taken, aud = apply as directed
- aaa = apply to affected area, per = by/through, c = with, s = without, dc = discontinue, tud = take as directed
- x 7d = for 7 days
3. Routes of Administration
- po = by mouth, sl = sublingual (under the tongue), iv = intravenous, im = intramuscular, sc/sq = subcutaneous
- ou = both eyes, od = right eye, os = left eye, au = both ears, ad = right ear, as = left ear
- pv = vaginally, pr = rectally, id = intradermal, td = transdermal, ia = intra-arterial
4. Dosage Form Codes
- tab = tablet, cap = capsule, cr/cre = cream, oint/ung = ointment, lot = lotion
- inh = inhalation, inj = injection, gtt = drop, syr = syrup, sol/soln = solution
- supp = suppository, susp = suspension, odt = orally disintegrating tablet, er = extended release, dr = delayed release, ec = enteric coated
5. Prescription Order Codes
- qs = quantity sufficient, daw = dispense as written (no generic), nr = no refill, r x 3 = refill three times
Units of Measure Abbreviations
- tsp = teaspoon, tbsp = tablespoon, ml = milliliter, oz = ounce
- mcg = microgram, mg = milligram, g = gram, u = units
Roman Numerals in Sig Codes
- ss = ½, i = 1, ii = 2, iii = 3, iv = 4, v = 5, vi = 6, vii = 7, viii = 8, ix = 9, x = 10
- l = 50, c = 100, d = 500, m = 1000
Example Sig Codes
- ii tab po tid = take 2 tablets by mouth three times a day
- i gtt od bid = place 1 drop in right eye twice a day
- aaa ud hs x 7d = apply to affected area as directed at bedtime for 7 days
- i cap q4h prn = take 1 capsule every 4 hours as needed
- i supp pr qid prn = insert 1 suppository rectally four times a day as needed
- 5u sq qpm pc = inject 5 units subcutaneously every evening after a meal
Prescription Examples
- Lisinopril 20 mg tab 1 qam #30 r x 3 = Take 1 tablet every morning, dispense 30, 3 refills.
- Amoxicillin 250 mg/5ml susp 3ml tid x 10d qs nr = Take 3ml by mouth three times a day for 10 days, dispense quantity sufficient, no refills.
Key Terms & Definitions
- Sig code — standardized prescription abbreviation based on Latin
- prn — as needed
- qd, bid, tid, qid — once, twice, three times, or four times a day
- q6h — every 6 hours
- po — by mouth
- qs — quantity sufficient
Action Items / Next Steps
- Review and memorize key sig codes and their meanings.
- Practice interpreting prescription directions using provided examples.
- Watch related videos on calculating quantities to dispense.