Abstract: A system for generating targeted advisory messages for pharmacy patients based on selected monitored data components of each transaction. When a pharmacy computer prints transaction data, the system monitors the data using printer data capture hardware interposed between the pharmacy computer and its printer. An additional processor compares selected components of the monitored transaction data with preselected combinations of the these components in a database. The database associates the preselected combinations of transaction data components with advisory message components retrieved from the database and used to build an advisory message for output to a printer, which may be the pharmacy computer or an additional printer.