Firstly: don't stop taking any medications without first discussing it with the prescribing clinician.
I don't believe there's been a whole lot of research on individuals taking
bupropion with an antipsychotic, because I don't think bupropion would be commonly prescribed to people with schizophrenia, nor bipolar disorder.
I'm not an expert, but the way I understand things is that it's not just a question of "
dopamine increase" or "dopamine decrease" when it comes to a
drug's actions --
drugs increase or decrease neurotransmitters
in specific areas/pathways of the brain.
So, my thoughts are that the bupropion increases dopamine in some area(s) of the brain, while the methotrimeprazine decreases dopamine in other area(s). This way the two drugs wouldn't be working against each other. I don't know, this is just a guess.
On the other hand, you are correct, you are blocking dopamine receptors, while at the same time increasing re-uptake/release of dopamine. Bupropion could be considered a stimulant, and antipsychotics are the ultimate anti-stimulant (called the "major tranquilizers" while benzodiazepines are known as the "minor tranquilizers"). To me that suggests you are working at cross-purposes here.
Another thing you might want to consider -- bupropion is well known for it's ability to lower the seizure threshold, but antipsychotics lower the seizure threshold as well. (see Haloperidol U.S. prescribing information at Pfizer website for example)
Just these two drugs alone, you might not need to worry about, but if you have a history of seizures or epilepsy, or are doing other things that might lower your seizure threshold, like taking
stimulants,
alcohol, or some types of
opioids, then this is something you should discuss with your clinician.
Finally, as someone who has taken bupropion with an antipsychotic, I can tell you anecdotally that both drugs will still work (to some extent, in my case).
So, to summarize:
Isn't levomepromazine going to mess up with the antidepressive effects of bupropion?
Quite possibly.
They are counteracting each other, right?
Not necessarily.
Is it a good idea to stop taking the levomepromazine?
Not without speaking with you physician/NP/whoever-is-prescribing-it-to-you first.
