How long does it take xtandi to work?

Just wondering how long it takes for xtandi to work, and if it works, how do you know? I thought it would lower the PSA value as a way to track progress. Been taking it now for two months and I'm not seeing any improvement to the PSA. My overall health appeared to be getting better from being off of chemo for 3 months, many of the severe side effects from chemo have gone away, but I thought there would be some change or reduction in PSA after taking the medication (Xtandi) for two months.

This last Xgeva treatment, after taking it every month after starting chemo, never had a reaction to it, maybe a little back pain for a day, but bone mets there would take pain meds for and usually handled it, last Xgeva treatment cause severe chest pain surrounding the liver, hurt to sit, hurt to lay down, Doc's Nurse recommended take pain meds every 4 hours instead of 8, seemed to help over 3 days and pain finally subdued below the notice threshold, breathing fine, no bone pain. However the two days of pain with last Xgeva was scary since chest pain started on its own, even areas not hurting my mets areas back and hip.

Since starting xtandi have been getting upper neck pain and I also started getting jaw pain barely under the radar, didn't hurt all the time but would have a throbbing pain in lower jaw that caused pain above upper eyebrow, before this medicine never suffered from headaches, so when I got any headache, I knew it was a new side effect of treatment. Problem is that it isn't tooth pain, as I've had all my teeth removed and permanent upper and lower arches put in, so any jaw pain makes me concerned that Xgeva may be the cause of the jaw pain, brought on by the neck pain of xtandi. I can live through the pain so far, but shure would like to see improvement on PSA once, just once post chemotherapy failed to work, 7 weeks into Xtandi psa is still doubling, now it started before chemo at 2.6 and had risen to 5, then to 9, then to 20, 30, 45, and now to 64, I keep seeing psa double.

Like some input. many of the answers I've seen here tended to be from older threads, would like to get more current suggestions.

Any idea what they consider time for the body to had enough time to get a result? I think there has been some good with xtandi, just not sure whether its failed or not. I brought up the Jaw pain to the doc this month during our meeting today, and was told xgeva will be discontinued until after the dentist checks for damage or if they see something in a whole body scan as I have a ct scan scheduled later this month. The chest pain I got out of the last xgeva shot is enough to set it aside unless its doing some drastic good, came close to going to ER day after the xgega shot (was on a weekend)

The Oncologist wants to give it 3 months so at least another month of Xtandi, I don't mind it and the cost is pretty much covered so at least the expense isn't bad to me. Unlike others. Doc mentioned other chemo solutions to try down the road, but i'm not eager to go through lots of chemo again, has only been a few months since they quit taxotere, which held it check for a few months but PSA's started rising again after six injections. If it is supposed to knock psa's down as soon as you start it, I definitely haven't seen that yet, each month showed raising numbers since starting it. But I'd been told radiation would lower it and it didn't either, never got below 2.6 although it was a decrease from 5.7 and its been uphill from there.

Guess It didn't work for me as far as reducing the psa values, may have slowed it some, and it helped reduce bone met spots i'd been feeling before. Just finishing up the 2nd bottle of xtandi, have a 3rd bottle here already, not sure if its worth it to take another month, but doc says to so will choke these pills down if I have to. Getting a bit frustrated that nothing seems to work, give everything 3 months to 6 months and while last two scans looked good, I'm thinking I'll see mets in the liver as I'm now getting pain in the liver I hadn't before the last xgeva shot. liver was involved with bright spots but didn't feel any discomfort, now i'm getting daily pain from the liver so have started taking pain meds again, at least at night.