Hi Lesley - Did some research. This is what I found; it explains about why they emphasize the last two tablets-   AstraZeneca is pleased to announce that starting June 2, 2008, ARIMIDEX will be available in a calendar blister pack called the ARIMIDEX PACK. The ARIMIDEX PACK is designed to be a useful tool to help remind patients to take their medication every day, and to help you when talking to patients about the importance of adherence. Patients will receive the same tablet and dose of ARIMIDEX as before, but in a more convenient calendar blister pack. The two tablets marked FINAL Tablet should be taken, one each day for the last two days of this 30 day pack. The final tablets help to remind patients it's time to refill their prescription. As of June 2, 2008, AstraZeneca will be dispensing ARIMIDEX only in the ARIMIDEX PACK