Patient Safety & Quality AssuranceQuestion 54 of 100
A prescriber writes an order for an oral liquid antipsychotic as "1.0 mg by mouth at bedtime." Why is this way of writing the dose considered unsafe?
a.If the decimal point is missed or lost, 1.0 mg is read as 10 mg, a ten-fold overdose
b.Doses below 10 mg must always be expressed in mcg
c.A decimal point is never permitted in an order for a liquid medication
d.The trailing zero shows the dose was rounded and is therefore only an estimate
Explanation
A trailing zero adds no clinical information but creates real danger: if the decimal point is faint or lost in transmission, 1.0 mg is read as 10 mg. The safe convention is the opposite pair of rules: never use a trailing zero (write 1 mg), but always use a leading zero for doses under one (write 0.5 mg, not .5 mg). Small doses are not converted to mcg simply for being small, decimal points are allowed in liquid orders, and a trailing zero says nothing about rounding.
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