Doxepin

[Guest KiminOrlando]

My allergist prescribed this for my random rashes, but now my bp has dropped and I'm having trouble walking again. Anyone tried this? I thought it was an antihistamine, but turns out it is for anxiety. The theory is that my sympathic nervous system has just been overstimulated and is randomly creating rashes. I think this med is the cause of my bp problems. But I can sleep at night and that buzzing/vibrating feeling is gone. 

[Pistol]

@KiminOrlando - I looked it up on the FDA website. It is NOT a antihistamine but rather it is similar to an antidepressant that inhibits norepinephrine reuptake. It is known to be an antihypertensive, therefore dropping your BP. Apparently if you take a low dose it can be given with Guanethidine to stop it from dropping the BP. Here are quotes: 

 

The current hypothesis is that the clinical effects are due, at least in part, to influences on the adrenergic activity at the synapses so that deactivation of norepinephrine by reuptake into the nerve terminals is prevented. Animal studies suggest that Doxepin hydrochloride does not appreciably antagonize the antihypertensive action of guanethidine. In animal studies anticholinergic, antiserotonin and antihistamine effects on smooth muscle have been demonstrated.

At clinical dosages up to 150 mg per day, Doxepin can be given to man concomitantly with guanethidine and related compounds without blocking the antihypertensive effect. At dosages above 150 mg per day blocking of the antihypertensive effect of these compounds has been reported.

 

https://www.drugs.com/pro/doxepin.html

Depending on how low your BP is dropping it may be not a bad idea for you? If you take any other drugs for hypertension maybe they can be adjusted to accomodate the Doxepin? 

[POTSius]

19 hours ago, KiminOrlando said:

My allergist prescribed this for my random rashes, but now my bp has dropped and I'm having trouble walking again. Anyone tried this? I thought it was an antihistamine, but turns out it is for anxiety. The theory is that my sympathic nervous system has just been overstimulated and is randomly creating rashes. I think this med is the cause of my bp problems. But I can sleep at night and that buzzing/vibrating feeling is gone. 

It appears that it is both an antidepressant and an antihistamine

see this article

https://www.medscape.com/answers/762917-36233/what-is-the-role-of-doxepin-in-the-treatment-of-urticaria-hives

Have you tried more typical antihistamines? Do they work on your rash?

Maybe you can take a lower dose? Maybe you will adjust to the blood pressure effects too

[Guest KiminOrlando]

I'm on an H1 and H2 blocker. I still got rashes. This was supposed to be the 3rd one. I'm only on 10mg and they are capsules so I can't cut it in half. I take the H1 in the morning, the H2 in the afternoon and this at night. My nose finally stopped running though. It was working so far. I just can't walk, stand up for long, keep blood flow to my arms/hands or stay awake. Calling the doc when I get more energy. Hands numb.

[Guest KiminOrlando]

So, Doxepin is a Mu Inhibitor. It turns out Mu Inhibitors are considered Intolerable Agents for some with POTS.