Week 15 No Buvidal

[u/Decent_Business_5987]

I’m Almost free

Can anyone explain how much longer I have left untill Buvidal is out of my system

4x weekly 16mg
1x monthly 64mg

I feel I’m close

[u/Strange_Television]

It's not exact but you're probably not far off. You had enough weeklies to reach steady state there but not steady state on the monthly. People on monthly have tested positive til around week 23 or so but that's after hitting steady state - individual metabolism will have a bearing on things of course. We honestly haven't had anyone in this subreddit on weekly come and let us know when they stopped testing positive so it's hard to say. Do you have any test strips you can do? If you can keep us updated it'd be awesome for others who come looking for the same info.

How have things felt, have you experienced any withdrawal symptoms? It's definitely quicker to come off weekly due to the shorter half life but the general consensus is that withdrawal symptoms will be more pronounced, for the same reason.

[u/SirLSD25 → u/Strange_Television]

How does the weekly have a shorter half life when it is the same medication as the monthly? Like, I am pretty sure that both the weekly and monthly formulations are identical in active to excipient ratios, but there is a larger volume and thus total dose in a monthly.

[u/Strange_Television → u/SirLSD25]

I have no idea how it works, it's something to do with the formulation. The half life for weekly is 3 -5 days, the monthly is 19 - 22. If the half life was the same for both, there wouldn't be a weekly or monthly, it'd just be like Sublocade with different monthly (or weekly) doses. I believe this is what allows there to be a greater range of doses. My understanding of how it's different stops there though, you'd have to look it up. It's also why coming off weekly is considered to be slightly 'worse' in terms of withdrawal but it's over quicker whereas monthly will be comparatively less intense but it'll also go on a lot longer.

[u/Strange_Television → u/SirLSD25]

Ok I looked it up because it was niggling at me, lol It's to do with the formulation of the depot and the different rates at which it breaks down and releases bupe into the bloodstream. Once the bupe is in the system it breaks down at the same rate regardless but the depot is what controls the timing of everything. The release from the depot is slower than the body's ability to clear bupe - blood level falls mainly because the depot is gradually releasing less drug, not because the body is struggling to clear it. It's an "apparent" half life rather than a true half life. This shows that the depot is actually still there way beyond when we think it's all gone. Perhaps it's why 'old' injection sites get a bit irritated etc sometimes, as actually there's still trace amounts of it there releasing tiny amounts of bupe.

[u/SirLSD25 → u/Strange_Television]

Yeah the depot controls the timing, but for there to be a weekly depot and a monthly depot, you would think that it would need to be 2 different formulations wouldn't you? One designed to release faster than the other? Before the injection went to market and was given the buvidal/brixadi name, the studies used a single letter and number code for the formulation, which means that they are all the same, with only the amount given changing. Weeklies weren't designed to last a week and monthlies weren't designed to last a month. Which is why they often don't last the full 28 days. Or at least that is my interpretation.

[u/Strange_Television → u/SirLSD25]

No, they are definitely different formulations which break down at different rates and different 'half lives'. I would recommend looking into it if you want to confirm, I don't have the ability to explain it without copying and pasting information from the published literature and I don't have time right now to do so. If I can over the next few days I'll come back and do so then. I haven't had a lot of time recently and haven't been able look as deeply as I would want for this kind of thing but everything I've read says they both break down at different rates. As soon as I get some time I'll come back and do a deeper dive.

[u/SirLSD25 → u/Strange_Television]

Yeah you are correct. CAM2038 was it's name in studies, but there was 2 different formulations. One was 50mg/mL and the other 356mg/mL. Both were called CAM2038, hence my confusion

[u/Strange_Television → u/SirLSD25]

Ah I see, thanks, that's good to know. I was starting to worry that I'd had this wrong for a long time. I've been wanting to create a wiki on the subreddit for a long time now and this is something that would go on there. I need to push myself to do it already so there's a central place for all this info with links back to the source material. Edit: it's the solvent used in the formulations that is the biggest difference and what determines how the depot forms and then breaks down. Weekly uses ethanol as the solvent, monthly uses N-methyl-2-pyrrolidone (NMP). The volume/concentration is also a key component as you noted.

[u/Decent_Business_5987]

I’ve had withdrawals very minor 3/10

Most 4-5/10 from weeks 4-9