Posted by ed_uk2010 on June 25, 2018, at 13:49:37
In reply to Re: Let's talk about combing SSRIs and TCAs » ed_uk2010, posted by TriedEveryMedication on June 24, 2018, at 14:39:30
> > >According to epocrates, this should kill me, either with serotonin syndrome or prolonged heart QT intervals or whatever.
Serotonin syndrome can occur when adding a strongly serotonin-elavating drug to an SSRI eg. an MAOI.
Desipramine is mainly a noradrenergic antidepressant, although one of its metabolites might act as an SRI like Link pointed out. Even so, severe cases of serotonin syndrome (rather than just serotonergic side effects) only occur due to combining two or more drugs which elevate sertonin by different mechanisms. That is why MAOI plus SSRI is such an issue. Even combining two potent SSRIs would generally only cause side effects, rather than a major case of serotonin syndrome. There is only so much you can elevate serotonin just via reuptake inhibition...
>heart QT intervals
This depends on...
a) does the two antidepressants elevate each other's blood levels through a metabolic interaction. For example, fluoxetine can increase desipramine levels, and desipramine prolongs the QTc interval.
b) do the individual drugs both affect the QTc interval? Most tricyclic antidepressants can increase the QTc interval if the blood level is high. Among the SSRIs, citalopram (Celexa) and escitalopram (Lexapro) are the ones which directly increase the QTc interval.
The main issue with your fluoxetine + desipramine combination is that fluoxetine can alter the metabolism of desipramine. Cautious desipramine dose increases are therefore important to avoid the risk of unexpectedly high desipramine levels - which could lead to cardiac effects. It sounds like you've had a blood level to check this. You can also do an ECG (EKG).
I am not aware of any cases of serotonin syndrome with your combination, and it would not be expected.
poster:ed_uk2010
thread:1099256
URL: http://www.dr-bob.org/babble/20180521/msgs/1099298.html