The use of decimal points in the prescription of medicines should be kept to a minimum.
When it is essential to use decimal points every effort should be used to limit to 1 decimal place only (ie 2.5 is acceptable 6.25 should be avoided).
The resulting volume of a dose in mg should also be taken into consideration and decimal points in the measured volume should be minimised also. e.g. morphine sulfate oral solution 2.5mg equates to 1.25ml which is very difficult to measure accurately and is best avoided, a 2mg dose with a resultant 1ml volume would be simpler without impacting on patient care.
BNF 65th edition March 2013 RPS and BMA
Institute of Medicine. To err is human: building a safer health system. https://www.nap.edu/read/9728/chapter/1
ISPM's list of error-prone abbreviations, symbols, and dose designations. Available at: http://www.ismp.org/Tools/errorproneabbreviations.pdf Accessed 19 Jun 2013.