getting a vaccine shortly after stopping mirtazapine leads to adverse symptoms

[xdc256]

No idea where this belongs, or if bluelight is the right place for it anyway, but Ill give it a shot...

I recently had a fairly bad reaction to a vaccine, mostly pounding heartbeat, sweating, chills, weird breathing, etc. It started within a couple of hours of the shot, and it lasted for a several days and hasnt really gone away yet. Since I had the shot the day before leaving for a holiday, I didnt bother to go back to a doctor and left for my holiday anyway.

I had been on a low dose of mirtazapine for a while before that (mostly for sleep), but I figured I would stop it since I wasnt sure what the deal was with bringing meds with me overseas. I stopped it a few days before I had the shot, and I didnt have any problems or wd symptoms stopping it.

My question is this: since mirtazapine is a strong antihistamine, could the cessation of a strong antihistamine shortly before a vaccine shot cause any problems? Does anyone know anything generally about histamine and vaccines? I gather histamine is involved in the immune system but I dont know much beyond that.

Thanks.

 

[amapola]

The nurse probably have asked if you had been taking any other meds before giving you the vaccine and told you to see a doctor if you had any lingering or severe side effects as you experienced. I don't know what we are going to be able to help you with other than saying to go see your GP. Could have been a reaction to the vaccine, withdrawal from the mirtazapine, a combo of them both, or maybe you just caught a virus while at the place (hospital/clinic?) receiving the meds.

I'll move this over to Other Drugs forum for you.

homeless >>> OD

 

[xdc256]

All sounds possible, though I really doubt the withdrawal from the mitrazapine in isolation has anything to do with it, since Ive only really been using low doses for sleep, and Ive started and stopped a number of times without any problems.

I guess I just want to know (if there are any of the more scientifically minded out there) if there would be some kind of rebound histamine effect (or the opposite?) after stopping the mirtazapine, and if so, would that interact in any way with a vaccine?

 

[amapola]

Antihistamines are histamine receptor antagonists which out-compete histamine. Prolonged use can desensitize the receptors to the antihistamine but I'm not sure how this relates to a rebound effect etc.

When a vaccine is given it acts as an allergen which your immune system kicks into gear creating antibodies to fight it. The antibodies then attach to the intruder and release histamine in the process. Depending on the vaccine the allergen is usually dead so things are designed not to require much of a response other than to store the antibody away and better recognize the virus if your body encounters it again.

If your receptors were sensitized to histamine then I suppose your reaction to the shot could have been worse because of the discontinuation. I think that the fact it has lasted multiple days and still hasn't gone away would not support this though.