1. A system for dosage error verification of unit strength errors, comprising: means for receiving prescription data relating to a prescription; at least one database storing data of unit strength error pairs; and a processor functionally coupled to the means for receiving prescription data and the at least one database, and configured for executing computer program instructions to: receive a prescription transaction comprising a submitted drug product and a submitted strength of the submitted drug product; compare the submitted drug product and the submitted strength to unit strength error data residing in an error database; determine that the submitted drug product is a member of at least one error pair indicated by the error data; determine that the submitted strength is potentially incorrect based at least in part on strengths indicated by the at least one error pair, wherein the error pair comprises counterpart strengths for the drug product known to cause dispensing errors; and perform an edit action based at least in part on the determination that the submitted strength is potentially incorrect.