In the context of a prescription, "ODAC" is not a commonly used abbreviation or acronym. It does not correspond to any standard medical or pharmaceutical term that I am aware of. It's possible that "ODAC" could be a specific instruction or notation used by a particular healthcare provider, but without further information or clarification, it is difficult to determine its exact meaning. If you have a prescription that includes "ODAC," it is advisable to reach out to the prescribing healthcare professional or a pharmacist for clarification. They will be able to provide you with the accurate interpretation of the term in your specific case.