What does "au" stand for in prescription terminology?

In prescription terminology, "au" stands for "both ears." This abbreviation is derived from the Latin term "auris unica," which translates to "common ear," indicating that the medication or treatment should be applied to both ears simultaneously. This is particularly relevant when prescribing ear drops or other treatments that affect both ears, as it ensures the patient receives the correct dosage for each ear without ambiguity.

Understanding medical abbreviations is crucial for pharmacy technicians, as it facilitates clear communication regarding prescriptions and avoids potential medication errors. The other options are specific to one ear or are related to injection methods, which do not apply to the meaning of "au." In contrast, "ad" would refer to the right ear and "as" would refer to the left ear, while the term for intramuscular injection is entirely different and doesn't relate to ear terminology.