Fluoxetine 20mg to 10mg

[Purple Fish]

I’ve been on 10mg fluoxetine from 20mg for 6/7 weeks now and didn’t notice any difference until the last few days. I’m anxious on and off, worried about having something seriously wrong with my health. I can smell smoke on and off, so obsessed I’ve got a brain tumour. Crying, don’t want to do anything. Should I go back to 20mg?

[panic_down_under]

Should I go back to 20mg?

Imo, yes. Antidepressants (ADs) don't have a direct immediate effect on anxiety (also depression) the way benzodiazepines do for anxiety, or aspirin does for pain. Anxiety disorders are the emotional symptoms of atrophy of parts of the 2 hippocampal regions of the brain caused by high brain levels of stress hormones killing neurons and preventing the growth of replacements. They are essentially a type of auto-immune disorder. ADs work by stimulating the growth of replacement cells (neurogenesis). The new cells and the connections they form create the therapeutic response, not the meds directly. This is why ADs typically take 4-12 weeks to kick-in. Btw - the cognitive, behavioural (CBT, REBT, etc) and mindfulness therapies also work by neurogenesis.

To activate and sustain hippocampal neurogenesis the antidepressant dose needs to be high enough to saturate about 80% (https://pubmed.ncbi.nlm.nih.gov/15121647/) of the serotonin transporters (5-HTT) molecules. Unfortunately, there is no readily available test to determine the dose needed for an individual, but the minimum recommended dose should achieve 80% 5-HTT occupancy for most.

It appears that 10mg is below your neurogenesis sustaining minimum and you need to take at least 20mg/day. Also, taking sub therapeutic AD doses for extended periods increases the risk that they'll stop working.

[Purple Fish]

Thank you for the information. I’ve got an appointment with my GP so will also see what they say. Ironically as I’m replying now I can smell smoke!

[panic_down_under]

Unusual smells are a common withdrawal symptom of most SSRIs and sometimes an initial side-effects. It will usually quickly diminish once the dose is increased. Generally, real smoke will be different enough to distinguish it from the pseudo smell, but be extra cautious with anything which has the potential to cause a fire.

[Purple Fish]

Just had my GP appointment. Fluoxetine is going back up to 20mg. The smoke smell can be menopause which I take HRT for as I’ve been in full swing for sometime but can also be as you said ‘Panic_down_under’ fluoxetine withdrawal.