Ten days of the antibiotic clendamycin lowered my PSA for 3 months

I am a Stage 4 M1b prostate cancer patient who has been under treatment at MD Anderson for the last 3 years. In March, I had a root canal and was prescribed 10 days of the antibiotic clendamycin. My PSA decreased over the next 3 months to one-half the value that it was before. Then it returned to what it had been. Anyone else experience something similar after taking either clendamycin (or another member of the erythromycin family) or doxycycline (or another member of the tetracycline family)? For anyone who did, what was the reaction of your oncologist to this?

9 Replies

  • I seem to have noticed a slight response while on 10 days of tetracycline, it was my thought that possibly I had some other source of psa , maybe prostatatitis and the tetra reduced that, but who knows maybe it was a response in the cancer itself. I wish you the best, what treatments have you been on, I too was dxed stage 4 M1B&L in 2006.


  • Hi Dan! After my original diagnosis of Stage 4 M1b 3 years ago, I was treated with Lupron for 8 months, at which time it began to fail. Upon the recommendation of my oncologist at MD Anderson, I then became a participant in MD Anderson's Clinical Trial Protocol 2010-0070. It is a two stage clinical trial where in Stage 1 every participant receives Lupron, Zytiga, and prednisone, and where in Stage 2, each participant receives, via bernoulli experiment, either sunitinab maleate or dasatinib.

    If you don't mind, please let me know what treatments you have been on too. I'm curious since you have been fighting the battle for 10 years!

  • Oops, in my above reply I made a mistake. In the last sentence where it says "where in Stage 2, each participant receives", it should actually say "where in Stage 2, each participant ADDITIONALLY receives".

  • Hi Ed,

    DX June 2006, BPSA 148, GS 10 confirmed by J Epstien at John Hopkins.

    mets to skeleton and distant sites some later determined to be benign unrelated events Stage 4

    I was on zolodex which is same as Lupron starting in June of 06, with zometa, I agrued for Avodart and casodex since it was high grade and advanced eventually got it to make up adt3 . that fall I went to see Dr Myers for the only time, He added triple dose casodex, which gave me liver problems but lowered my psa down to 6 from 12 when I went to see him. Then I switched to nilandron at advice of Med Onc in Boston, liver #s did not come down so switched to estradiol patch to let liver recover, got a good response to estradiol that first time, switched back to Nilandron and got a good response, when that failed I added estradiol patch again as I had done several times since, then I had almost 2 years on High dose ketoconazole, all the while doing Avodart , zometa every 3 months and zolodex/Lupron, 5 years ago when it became available and keto was failing I moved to zytiga , which worked for a year , but I got more time when I readded climera estradiol patch to the zytiga, and 3 years ago I dropped zolodex and zometa and went to xtandi, which I am preparing to stop , as I have a laproscopic biopsy planned for Friday9/2 to see if I have certain mutations after all this time, Braaca 1 and 2 and several others to see if I can be a responder to a parp inhibitor called Olaparib, 33% of Men tested at my stage do have this and for the ones that do, Olaparib has been shown to give near 100% response rate, ( this discovery on Men with advanced pCA and Braaca 1 or 2 and several other mutations responding to Olaparib has only been out a year or so. The next week after laprocopic biopsy of one of the masses in my abdomen or pelvic area I week begin q21 docetaxol 9/7 which I have put off for 18 mos with a slow rise in psa, currently 60 with slight increase in scans. If it is found I have the mutation it will give me something to do after chemo less more chemo. I was so fortunate to be alive when drugs like xtandi and zytiga , rad 223, and others and of course to have the disease after Huggins and Hodges did their preliminary work back when.

    Thank You for asking, please excuse typos, I was a commercial fisherman in a different life from Cancer haha

    make the most of every Day


  • Hi Dan, Who is your Dr. in Boston?

  • who is he being treated by now?

  • Ed,

    See my "Tetracycline / doxycycline / minocycline" post of 8/31.


  • Outer Space---whatever works--is a hallelujah.


  • I have heard of an anti-biotic reaction to PSA. Unknown whether the reduction was really do to a cancer remission or possibly reacting to prostatitis.