The Joint Commission's official Do Not Use list
| Do not use | Problem | Write instead |
|---|---|---|
| U, u (unit) | Mistaken for 0, 4 or cc | unit |
| IU (international unit) | Mistaken for IV or 10 | international unit |
| Q.D., QD, q.d., qd (daily) | Mistaken for each other | daily |
| Q.O.D., QOD, q.o.d., qod (every other day) | Period after Q mistaken for I; O mistaken for I | every other day |
| Trailing zero (X.0 mg) | Decimal point missed | X mg |
| Lack of leading zero (.X mg) | Decimal point missed | 0.X mg |
| MS, MSO4 | Can mean morphine sulfate or magnesium sulfate | morphine sulfate |
| MgSO4 | Confused with MSO4 | magnesium sulfate |
Other error-prone abbreviations (ISMP)
| Avoid | Problem | Write instead |
|---|---|---|
| µg | Mistaken for mg | mcg |
| cc | Mistaken for U (units) | mL |
| SC, SQ, sub q | SC mistaken for SL; q mistaken for every | subcut or subcutaneously |
| HS | Half-strength or bedtime | half-strength or bedtime |
| D/C | Discharge or discontinue | discharge or discontinue |
| AD, AS, AU | Mistaken for OD, OS, OU (eyes) | right ear, left ear, both ears |
| IN | Mistaken for IM or IV | intranasal |
Common abbreviations you will still see
| Abbreviation | Meaning |
|---|---|
| PO | by mouth |
| IV, IM | intravenous, intramuscular |
| PRN | as needed |
| BID, TID, QID | twice, three times, four times a day |
| q4h, q6h, q8h, q12h | every 4, 6, 8, 12 hours |
| NPO | nothing by mouth |
| STAT | immediately |
| ac, pc | before meals, after meals |
Frequently asked questions
What is the Do Not Use list?
A list of abbreviations The Joint Commission requires organizations to stop using because they cause medication errors: U, IU, QD, QOD, trailing zeros, missing leading zeros, MS, MSO4 and MgSO4.
Why should you not write U for units?
A handwritten U can look like a 0 or a 4, turning 10 U into 100 units. Always write unit.