What it means
UD has been read as "unit dose." In one reported error, an order for a diltiazem infusion "UD" was given as a single large (bolus) dose. ISMP lists it as error-prone.
For the nurse
Write "as directed," and better still, write out the exact directions. Clarify any order that says only "UD."
Related terms
U
An abbreviation for "unit" that must not be used in medication orders; write "unit" in full.