Firmagon

[Raminagrobis]

i am trying to schedule a holiday and would like to know if it is bad to be 3 days late on my Firmagon shot or/ and if I can be 3 days early .Does anyone know ?

Thanks

[RyderLake2]

Hello,

I was on Firmagon (degarelix) for about a year. Because of difficulty scheduling monthly appointments with my family doctor for injections I was often out a day or two. Neither my doctor nor I was particularly worried about it.

[JohnInTheMiddle in reply to RyderLake2]

A nurse comes to my home to do the injection. And there are some people who even do the injection themselves. I have not wanted to do that because It's tricky.

[Raminagrobis in reply to RyderLake2]

great Thank you

[JohnInTheMiddle]

R. - Good question. I've been on Firmagon for two and a half years. I have noticed some doctors and a lot of people have a casual attitude to adhering to the 28-day schedule (I do 28 days and not a month, which means one extra injection per year).

Also it's worth noting that I have been encouraged to switch to Lupron - which is more convenient - which is a terrible way to make a medical decision. From a lot of reading I decided to stay on Firmagon.

Based on my own "research", two or maybe three days earlier or late for a Firmagon injection is okay. I have done this twice. And then I return to the 28 days schedule. My sense is that being late for a week etc. is not a good idea at all.

If you want to read about the topic then the term to add to your search strategy is pharmacokinetics. This relates to the behavior of the drug in your body and how long it takes to metabolize. What is the target maintenance level and how it decreases over the course of 28 days?

Recall that at the beginning you had two doses at the beginning. This makes sense - you boost up the Firmagon at the beginning.

So looking at what is the target level of circulating drug, we see a bit of a sawtooth pattern. It's metabolized and then we give it the next injection. The key thing seems to be that Firmagon is it is first released slowly from the depot in the fat under your skin, and then metabolized fairly slowly. So that a few days is okay. Two days delay is not going to result in a concerning drop in the level of circulating drug.

But if you look at the numbers with a delay of a week you begin to see that the circulating level of Firmagon is dropping to a concerning point.

It's interesting to compare injected Firmagon to the newer and very expensive oral daily Orgovyx/Relugolix. Both drugs are ADT antagonists (as opposed to ADT agonists such as Lupron).

With Orgovyx it's very very important to take your pill at the same time every day and to never miss a day. Because in contrast to our Firmagon, it is metabolized very very quickly. And testosterone production can rebound very very quickly, which then in turn stimulates androgen receptors on the surface of prostate cancer cells. And as you could see prostate cancer cells light up and start to do their wicked work. And then your PSA well show up as having gone up.

I've seen a lot of casual answers to this question. And I wanted understand this in more detail. The original clinical studies were 28 days - and I'd like to adhere to that. We all dread the development of resistance or the arrival of new evolutions are cancer. And the general idea is just "that it happens". But why does it happen?

I don't know - but I don't want to take risks and who knows, but it would be interesting to see if people who adhere more rigorously to therapy schedules have better results than people who take a more casual attitude.

I'd be happy if anybody can correct any of the notes above. I'm a lay person not a medical doctor or specialist.

In summary, my own personal conclusion is "2 days is okay and maybe three". Beyond that I get nervous. Somebody else might think that three days is too many!

[Raminagrobis in reply to JohnInTheMiddle]

thank you for your valuable comments

I have been on Firmagon for 14 months and always follow the 28 days appointments .

[Tall_Allen]

Better early than late. It's elimination half-life is 28 days.

[Raminagrobis in reply to Tall_Allen]

Thank you very much

Good to know

[Skoda1]

After the mess the nurse made of the first two injections I decided to do it myself and have now done 19. There are lots of guides in this site so I won't repeat the procedure. The 'trick' is to do everything very slowly and keep the needle in situ for at least a minute after emptying the syringe. Don't panic. Good luck and enjoy your holiday.

[JohnInTheMiddle in reply to Skoda1]

Bravo Skoda!! My wife did the injections for Lapelga (pegfilgrastim), the immune system booster used with each of my six Docetaxel infusions.

But I've been not eager to do my own Firmagon injections - there are very specific instructions and quite a sequence of events. So bravo you stepping up and doing it yourself!!

And as per your initial bad experience, Firmagon (degarelix) has to be done correctly - and if the injected depot gets into the muscle (instead of only belly fat) one can have quite a bad reaction in terms of fever and pain.

So I've been able to arrange a nurse that comes to my home every 28 days and he is fantastic and I never have any problems.

There's a quality control issue in my experience in terms of clinic or hospital injection consistency. I've had injections by a hospital nurse who had never done it before and who had had the procedure explained to them orally only five minutes previous.

One can note a lot of complaints about ADT reactions and especially Firmagon - I believe there's a possibility that much of the concern - and even a decision to stop the drug - may be due to a failure to follow correct procedure. I won't say incompetence.

[binati in reply to Skoda1]

Eventually owing to logistics problems and lack of trained nurses being always available I started to inject it myself. Did it for 6 months. No real problem.

[LongevityAT]

I asked this question of Ferring, the manufacturer of Firmagon, last year and I don't recall the exact answer but believe they stated you are OK within up to 10 days of the recommended 28 days between doses. Check with them to verify but I remember their answer removed any concerns I had on timing between injections.

[JohnInTheMiddle in reply to LongevityAT]

"within 10 days" - is a little casual. And what does that mean even? "Before and after", meaning a 20-day window? For 5 days before and 5 days after 28 days?And what about the impact on your full schedule? If you're following a 28-day cycle, if you are off by 10 days, however that is calculated, then what happens with your next scheduled injection? Do you move your entire schedule?

The randomized control trials that defined the value of Degarelix as a GnRH antagonist ADT does not specify any big window like this.

As Tall Allen has pointed out above, 28 days is the "elimination half-life". The elimination line is probably a curve, not a straight line. Also there's two phenomena going on here - one is the release of the drug from the depot, and then two, there's the metabolism of the drug as it circulating in your system. This is all the pharmacokinetics of Degarelix.

Consider that for Degarelix to work, you need a certain minimum circulating drug in your system. That's why you have two injections at the very beginning of your treatment.

From my own reading I'm confident that during the two or three days after the scheduled 28 day Degarelix date, that the level of the drug in my system has probably not fallen below the critical level. But I have read nothing that says 10 days is okay.

What about the big picture? Degarelix is a GnRH antagonist. That is to say it is fighting against the hormone pathway that leads to the production of testosterone. And testosterone is what stimulates your prostate cancer cells. To do their wicked work. And then after all this we measure the PSA that is produced by active cancer cells. PSA is only a "trailing indicator".

A lot of these hormone management phenomena are not "all or nothing". Some phenomena are dose dependent. So if your level of GnRH antagonist falls to a lower level - maybe you will get a little bit of resulting testosterone production! We would prefer no testosterone production!

I have also encountered various medical staff who were similarly casual about therapy schedules. PCa is not a chronic illness yet. It's a terminal diagnosis. And I prefer to follow as closely as practical the guidance from the randomized control trials.

[Gatodd]

I was on firmagon, got Covid the day before my scheduled shot at 28 days. My MO was not concerned about being a few days late (it was more than 3 days - I think it was 8).

The challenge with early is that insurance may not approve. I switched to Lupron after 16 months and wanted to get a shot a few days early rather than a few days late. My insurance required 84 days between Lupron shots.

[Healthunlocked133]

Great way to manage healthcare by the insurance companies. What do doctors know.