The link I've provided shows the same efficacy at lower doses including half the standard dose. Therefore my oncologist gave me the option of taking a full dose every other day or taking a half dose (half tablet) everyday.
https://www.drugs.com/pro/anastrozole.html
The half life is 50 hours so it wouldn't appear that there should be much if any significant drop-off in the level of the drug present in the body. In fact, because I was not tolerating the drug well, my oncologist suggested that I take the drug for 6 months and then take a month off. I no longer have the link, but I also ran across a study concluding that 9 months on and 3 months off had
the same or similar outcome as taking it continuously.