Some abbreviations get misread so often that they cause medication errors. The Joint Commission keeps an official Do Not Use list, and the Institute for Safe Medication Practices (ISMP) lists more to avoid.
The Joint Commission Do Not Use list
| Do not write | Why | Write instead |
|---|---|---|
| U, u | Mistaken for 0, 4, or cc | unit |
| IU | Mistaken for IV or 10 | international unit |
| Q.D., QD, q.d., qd | Mistaken for each other and for QID | daily |
| Q.O.D., QOD, q.o.d., qod | Mistaken for QD or QID | every other day |
| Trailing zero (5.0 mg) | The decimal gets missed, so 5.0 is read as 50 | 5 mg |
| No leading zero (.5 mg) | The decimal gets missed, so .5 is read as 5 | 0.5 mg |
| MS, MSO4, MgSO4 | Morphine and magnesium get confused | morphine sulfate or magnesium sulfate |
Other error-prone abbreviations (ISMP)
| Avoid | Write instead |
|---|---|
| µg | mcg |
| cc | mL |
| SC, SQ, sub q | subcut or subcutaneously |
| HS | bedtime (or half-strength) |
| D/C | discharge or discontinue |
| > and < | greater than, less than |
What to do when you see one
Do not guess. Call the provider to clarify the order before giving the medication.
Practice this in Pharmacy
Spot QD, U, and trailing zeros on real-looking prescriptions.
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Quick answers
Why is QD on the Do Not Use list?
QD can be misread as QID (four times a day), which could lead to giving a drug four times as often as ordered. Write "daily" instead.
Why should you never use a trailing zero?
If the decimal point is missed, 5.0 mg can be read as 50 mg, a tenfold overdose. Write 5 mg.
Evidence & Clinical Sources
Reviewed against current guidelines and drug labels. Always follow your program, a current drug reference, and facility policy. Our sources policy
For learning only. Lab ranges and policies vary. Always follow your nursing program, a current drug reference, and your facility's policies.