In medical dosages, the acronym “mcg” stands for micrograms, though it is occasionally confused with the abbreviation for milligrammes, or “mg.” According to the U.S. Food and Drug Administration, one microgram is equivalent to one thousandth of a milligramme.
In order to decrease incorrectly understood abbreviations for human and veterinary medicine, the FDA and the Institute for Safe Medical Practices teamed up in 2006. According to the FDA, written prescription abbreviations are confusing and a cause of avoidable medical mistakes. The use of abbreviations makes writing prescriptions more effective, but they are sometimes misconstrued because of the differences between veterinary and medical education and training, as well as bad handwriting.
The FDA states that the Latin apothecary and avoirdupois systems are the two abbreviation systems used in medical and veterinary institutions. The Center for Veterinary Medicine also discovered that the terms once daily, abbreviated “SID,” twice daily, abbreviated “BID,” and four times daily, abbreviated “QID,” are incorrectly understood, leading to a disparity in the amount of medication that patients are administered.
Other problems with prescriptions include interpreting trailing zeros incorrectly and misunderstanding the “U” in micrograms for a unit. According to the FDA, a pharmacist’s mistake of “5.0” for “50” results in a tenfold increase in the medication’s prescribed dosage. Also stated is a tenfold increase if the “10U” is misunderstood for 100 units