Fluoxetine withdrawal symptoms

[jonowalks]

Hi guys

Started a course of fluoxetine about two weeks ago, 20mg daily. I managed to last 10 days before the side effects got unbearable, the usual sweating, 100% worse anxiety and depression, the metallic taste, sore jaw, the whole she bang. On speaking with my doctor she swapped me out for sertraline this Monday just gone but after my last fluoxetine on Monday morning I decided to cut them all out.

The reason for the post is that I've had some terrible withdrawal symptoms. Mainly I feel exhausted, had all kinds of aches and pains, still have the metallic taste, a lot of dizziness, tons of anxiety and depression and worse of all I have really twitchy legs and arms. They seem absolutely full of energy. Has anyone else had similar experiences? And how long can I expect them to last? It's doing my health anxiety absolutely no favours!

[MrsCav]

I'm not to sure if the Fluox is still in your system, there are other posters much more well informed than me .... but if I hazard a guess, I would say very little if any is still in your system. Your withdrawal symptoms sound like anxiety symptoms .... you have to remember that the meds take a while to get into your system and all the while the anxiety is getting worse too .... sods law n'all that.

[MyNameIsTerry]

Are you saying that your GP decided for you to stop the Fluoxetine last Monday and start the Sertraline immediately?

Your Fluoxetine wouldn't have become stabilised in your blood plasma in such a short time. It's documented that 7 days later after discontinuation the drug will drop 50% in your brain. However, not all of this even developed in your case as you didn't get beyond the 5 week mark. But it will take some time to be eliminated and that's why switching meds means a 7 day "washout" period when switching from this particular SSRI because it's half life is so long unlike the others. This is why I'm asking about the Sertraline.

Since it's unknown how much of the drug has increased in your blood plasma as you cut it short, we could assume you are classed as "acute" rather than "chronic". This would mean putting it at a half life of 24-72 hours. Using a standard pharmacokinetic calculation (but all drugs vary and it is individual due to your capacity to eliminate a drug) you could multiple this by 5 to get the drug to <5% in your blood plasma which is considered "clinically insignificant" or multiple by 7 to get it to 0%. This could put it (at 5%) between 120-360 hours or 5-15 days.

The active metabolite takes longer. After multiple dosing, but not to reach steady-state levels (which would mean chronic use) this would be about 9.3 days (although it is also quoted between the range 4-16 days between acute to eventual chronic use) so multiple this by 5 and it gives you 46.5 days. However, I'm not sure why they have both 4 and this, so it could be lower?

However, each half life sees it drop by 50% of the previous level e.g. at 1 half life it is 50%, by 2 it is 25%, by 3 it is 12.5%, etc. So, whilst it may seem a long time for this med, it will be eliminating itself fairly quickly down to a lower level so don't look at these timescales and think it's going to be hard all the way because your body is eliminating it efficiently.

As MrsCav mentioned, you went through hell going on this med and that will have messed you up so along with this med being eliminated, you have been put into a higher state of anxiety and this usually requires a bit of time of it's own to level out.

[MrsCav]

Terry, do you have any idea how long it takes to get into your system?? Or mine, in particular. I was on Fluoxetine till around Autumn of last year, I thought I had slow tapered, however, it looks like I didn't taper long enough as my anxiety came back around December. I lasted about a month before I realised I needed the meds because A) I knew the anxiety/intrusive thoughts where winning and B) I knew I could get better and I prefer me on fluoxetine. I reckon I was off for about 3 months. I have now been taking it for 3weeks +1 day. It's definitely been easier this second time around, but I seem to have good and bad days.

[MyNameIsTerry]

Hi MrsCav,

I know what you mean, my GP took me off Citalopram and 6 months later I had a full relapse...which I'm still dealing with. I was doing pretty well before that.

Yes, Fluoxetine is pretty well documented in terms of how long it takes, unlike some other SSRI's.

The first hurdle is getting it to "steady-state" (as much going in as coming out). This is known to take 4 week with this med, it's much shorter with the others.

Studies have shown the brain concentration levels are still developing to their potential in week 5.

Some people on here seem to have a wobble around week 5 and I wonder whether that is because they have finally reached steady-state because at this point you have the most consistent levels of the drug in your blood plasma. I've noticed some people starting on other SSRI's say week 2 was hard and in those ones they would have reached steady-state in <9 days depending which med it was.

So, I would hand in there. Until you get past this alone you aren't getting the full meds potential anyway.

Now interestingly these meds tend to work in two stages. The first stage is just flooding the space with Serotonin rather than it passing out through the receptor site but the second stage fills in some of the holes in the receptor site, like when a shower head gets fuzzed up, and this is the long term gain we need. I can remember seeing a study where it showed this at the end of 30 days but it would have been one of the shorter half life SSRI's, not yours. So, I expect it will take a bit longer but can't be sure without looking into it. But then, they tell us to stay on meds for much longer anyway to see the real changes since that truly comes from our brains changing from anxious thinking.

[MrsCav]

Thank you, so a couple of weeks still to go then.

The first time I took fluoxetine I hit the dreaded 5 week blip. It was horrendous. I ended up on Propranolol. This time around I am taking them both - thought it better to hedge my bets. I'm definitely reacting better to the Fluox this time around but that could also be just because I now know what is a side effect and it doesn't bother me the same.

Anyway, thanks again Terry. I beat your score on Something Fishy too .. I am so proud of myself. I need to get out more

[MyNameIsTerry]

I remember when I went on Citalopram the first few days were very hard but also that second week was a bad one too. That was when my med was at steady-state but in week 3 it started decreasing.

On my current med I found it ramped up very quickly when I crossed the adrenaline threshold (It's a SNRI) and those 8-10 days were the worst of my life - by far. This SNRI has quite a short half life and looking back with what I know now, I would have reached that steady-state within 3 days. I can definitely remember the 2nd half of those 8-10 days been worse and the last 2 mornings I resorted to a Diazepam (2mg) when I woke. I had resisted taking them all through and I never took the Zopiclone either (I needed that on the Citalopram but my GP gave me bad advice and I ended up dependant).

So, my patterns look that I struggled when I reached steady-state for a week or so on Citalopram and about 7-8 days on Duloxetine.

I guess that ties in with the 5th week issue people on here have reported. If that only lasts a week or two though, at least you know what it is and why.

I think your attitude is the right way to be - expect side effects and go in to it with your eyes open, be reasonable. I had no idea about anxiety the first time and my GP told me my side effects may be "mild sweating and some loose stools". Well that's pretty far away from the depression, insomnia, being so hungry but unable to eat, increased anxiety, etc. I struggled badly.

When I went on Duloxetine when I relapsed years later (had been off Citalopram for about 6 months at that point) I knew it would be tough. I handled the 30mg SSRI type dose of it pretty well (you have to taper up to 60mg for GAD...and I know why after going through that hell!) but the 60mg was very tough and it hit me like a train the next morning. I had the nausea when taking it at 30mg though, I was over the toilet within 30 minutes. This 60mg dose was bad as it was all adrenaline rushes so the anxiety was truly awful, no depression or insomnia at all. I was very surprised with the latter since I couldn't even sit down for hours in the morning as I was so agitated. But I knew my GP couldn't help and it was a switch (and probably toughing it out again) or just hanging on. I didn't ask for help, unlike before, I gritted my teeth and stuck out those horrible non stop days telling myself 'any day now it will break and subside' like it was a fever. It did, and it was a fair relief.

Common side effects are 1 in 10 in the leaflets. But that's 1 in 10 for that side effect. As you know, there could be 20 of them in that group so that's hardly a 1 in 10 chance and the probability of side effects is high.

I firmly believe going into this with the right attitude is the way, just as you are doing.

[MrsCav]

My very first anti d was Citalopram, I lasted about a week. Then I took nothing for a while and really struggled, but I was struggling with what was 'wrong' with me. I know I have always been an anxious person - my husband says I ask too many questions, that isn't him having a go, that's his observation - so I guess I didn't realise the anxiety was getting out of control.

But I noticed it very quickly this second time around. I was happy to go back on Fluoxetine. Like I said, I prefer me on these tablets. It's just the waiting for all the side effects to be over.

You're a diamond with all the information on how meds work.

[jonowalks]

Wow Terry! That is some legit science right there!

The doctor did specifically state that I could start on the sertraline the very next day. Thankfully I didn't agree. The symptoms of withdrawal or uptake or whatever it is making my body play up seems to have calmed down to a manageable level now. Still get anxious in the afternoons until bedtime but I fear that may be a habitual state I get in mentally anyway.

[MyNameIsTerry]

I think you should have a look at the guidance to doctors because that's not how I understand a switch from Fluoxetine to Sertraline:

http://www.gpnotebook.co.uk/simplepa...?ID=1651179592

You will see NICE mentioning the washout and the NZ formulary. The latter follow the Maudsley Guidelines and this a well known mental health unit in the UK.

If you look for your local trust, you should be able to find their antidepressant switching guidelines to their region. I've looked at several trusts and found they match those in that link.

The advice could be construed as switching from the 4 week mark where GP's are reviewing but that would be an assumption. GP's are well known for their lack of understanding of these meds, something seen on here all the time. Personally, I tend to go with the directives to them...which GP's can often be seen not following.

I think you have done the right thing. That washout period is the minimise the risk of Serotonin Syndrome. That's classed as a Major risk in any cross taper anyway and considering not having a washout period in short half life SSRI's, it is ok for GP's to just monitor for it but with Fluoxetine the half life is far too long when you start adding a full dose of a short acting SSRI on top of that. There must be good reasons why people are advising the washout period and this advice is coming from people with more expert knowledge than any GP would ever have.

It's good to hear things are settling down. Like I said above, whilst it takes quite a while it will be dropping quite a bit initially and this will probably be why.

GP's are not fond of people doing their own research so you could ask a pharmacist. They will have to accept their advice I would think as they know more about meds and interactions than GP's.