Total knee replacement and breast cancer here (tamoxifen/zometa) my dr gave me 4 pills (keflex 500mg) to take 1 hour before dental work. is this ok? it seems like a lot all at once?

It is okay to take the medication as prescribed. It is to prevent infection in case of breach or contamination of the blood during surgery.

That is the typical dose prescribed for prophylaxis prior to dental procedures. It is meant to protect from a prosthetic joint infection as germs can cause a transient bacteremia during invasive dental procedures.

It's the appropriate dose. Trust your practitioner to have your best interests at heart.

This was the protocol up until July of this year, now the ADA recommends no antibiotic prophylaxis prior to dental appointments for any joint replacement. This is a source of confusion for many orthoepic surgeons and dentists especially with the new recommendations