What Affects Alpha Receptors More? Trazodone Or Mirtazapine?

Hello.

I need to know which medicine will have a greater affect on the alpha-1 adrenergic receptors.

Do we know that the higher number means it would therefore have a greater affect?

Binding profile lists are from wiki.

Trazodone

Ki(nm)
α1A 153
α1B ND
α2A 728
α2B ND
α2C 155

Or Mirtazapine
Ki(nm)
α1A 500
α1B ND
α2A 20
α2B ND
α2C 18

If you are curious as to why I want to know this, I have a disease called POTS which is now believed to involve antibodies which act as alpha-1 antagonists. So it would then follow that being on an alpha antagonist (which both trazadone and remeron are) would not be ideal.

I really really appreciate any info, Thank you

P

I have POTS as well as neurogenic orthostatic hypotension and autonomic failure if you ever want to talk more about it. You want to avoid anything that lists orthostatic hypotension as a possible side effect (some of the SSRIs, trazodone, remeron, the atypical antipsychotics, most of the TCAs etc).
This is going way back to pharmacology in med school, but I believe trazodone bind more preferentially to the alpha adrenergic sites than does remeron. Not positive. They both have alpha adrenergic properties.
I don't know what treatment you're doing for your POTS. For my various autonomic dysfunctions, I'm on droxidopa, midodrine, florinef, use compression stockings, have elevated the head of my bed, stand up veeerry sllooowwwllly and get every other day IV saline infusions. All of this has more or less stopped the almost daily fainting episodes I was having and I'm asymptomatic a lot of the time and am able to do pretty much whatever I want to (when I'm not in the stupid hospital).
Like I said, PM me if you ever want to discuss it further. I've kind of made it a personal mission to read every article ever written about POTS, neurogenic orthostatic hypotension and autonomic failure, so I've learned a lot...

Im in the same category as you meaning ive really immersed myself
into all of the published info about POTS. I feel based on the new research, leaked info, and success of midodrine, that POTS is clearly its own sutoimmune disease classified by alpha antagonistic and beta agonistic antibodies. Unfortunately for me I just cant sleep without trazodone or remeron.. Unless i take xanax. I also take melatonin and benadryl nightly. I really need to know the lesser of two evils, traz or rem, when it comes to which is more of an alpha antagonist. I think youre right, its probably traz. I think a lower number means more of an affect. I also think the 'cure' for pots is PEX, IVIG or maybe prednisone combined w exercise.

Is there some kind of "POTS epidemic" going on at the moment? My sister told me that there are 3 teenaged girls on their street who have POTS. One of them is in a wheelchair and can no longer attend school.

I was diagnosed with CFS in the early 90s and had the NMH problem. It's much better now than it was then but still a problem.

Thanks for the info about alpha antagonistic and beta agonistic antibodies.

Hi pande882

The smaller the Ki number, the stronger the interaction between a drug (or anything else) and a protein (eg, alpha-1 adrenergic receptors) is.

So, from your data:

Trazodone has a stronger interaction with α1A than Mirtazapine (Ki values of 153 nM and 500 nM).

Trazodone has a weaker interaction with α2A than Mirtazapine (Ki values of 728 nM and 20 nM).

Trazodone has a weaker interaction with α2C than Mirtazapine (Ki values of 155 nM and 18 nM).

It sucks, right? I'm done the steroids and IVIG with limited success. Honestly the thing that's helped the most is the three times a week IV saline infusions. And I drink plenty of water, but the IV part I guess is supposed to improve the cerebral perfusion that's diminished a lot of times in POTS. I've taken both remeron and trazodone and had a lot more issues, a lot more morning after fainting episodes with trazodone if that helps any. What's PEX? I'm not familiar with that?

I think it's just being recognized more frequently. Kind of like the ADHD "epidemic". Luckily, most adolescents improve within the couple years vs. adults who don't. I hope the girls on your sister's street do. There's a lot of research and a new drug for neurogenic orthostatic hypotension (which I have as well), and I think that's kind of triggered more research and knowledge into all types of orthostatic hypotension and their associated disorders. Just my opinion.

Personally, I think trazdozone is the best sleep aid out there, but I just can't do it. I've taken a couple others - Seroquel and Elavil with still some symptoms (they too have alpha adrenergic properties), but the side effects were less and they worked great for sleep. The only reason I stopped either one is because I have issues with a long QTc due to an eating disorder and they can prolong it, which could kill me, so probably not the best drugs for me, but they did work great....

Thx for the responses. Wish you well pinkflower and thanks kiwi for the info!

POTS blows but the medical advances lately are so promising!