Mirtazapine and diarrhea?

daftcat75

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I started Krista on transdermal mirtazapine (Mirtaz) and she started eating well as expected. But this morning she had some diarrhea. I see this side effect in only 6% of trial cats from the insert. Which is the same as the control group. On Google, I see it listed as a side effect only in the context of serotonin syndrome. But I don’t see any other signs of that. No vocalization, no increased affection, she’s a little restless but I think I’d be too if I went through what she did in the litter boxes.

And now she’s sleeping off the whole incident and her breakfast.

I’ll contact the vet when they open. For now, I’m thinking we’ll skip a dose (we only just started yesterday) and give her s boulardii today to see if that resolves the diarrhea.

She did have clostridium in the summer. If she has more diarrhea/loose stools, I’ll send off a sample for PCR.

I’m hoping it’s not that though and was looking for other reports of mirtazapine (or Mirtaz) and diarrhea to help put my mind at ease.
 

shebaa

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was she not eating before the medication? if so, maybe she ate too much too fast. if it was my kitty dont know if i would stop the medication just yet. maybe she just need increase eating slowly if she wasnt eating before.
 
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daftcat75

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was she not eating before the medication? if so, maybe she ate too much too fast. if it was my kitty dont know if i would stop the medication just yet. maybe she just need increase eating slowly if she wasnt eating before.
Eating too much too fast would come back up. I'm already right-sizing the portions for her pre-medication nibbles.

This is the first time we tried the transdermal and the dosing is not very accurate. It is possible that this is just a side effect of getting too high an initial dose. I see diarrhea as a side effect of serotonin syndrome

It is also possible that this is a return of the clostridium she had earlier this summer.

I can't let her stuff her face if it isn't being digested. She has only had one dose of this medicine. If it was just the medicine, we try again with a smaller dose when her diarrhea has stopped. And if it's clostridium, well, her diarrhea could persist for a long time and it wouldn't be wise to feed her regular food until that's under control.

I will pick up some turkey breast to poach for her in case this isn't a one-off.
 

mrsgreenjeens

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Hmmm, as I recall, when Callie was on transdermal Mirt, we were still only to give it to her every few days, like the pill form, AND, if memory serves, it was also in some sort of syringe that was pre-dosed so we couldn't give her too little or too much. We just put on latex gloves so none went into whoever was rubbing it into her ear, put it on the fingertip of one of the gloves and then started petting her like she loved. Then when she was "into it", would swoop it into her ear and she was none the wiser as we rubbed it in well. (she loved the inside of her ear to be massaged!) Anyway, she never had diarrhea from it. .

Because of that experience, now I make sure I massage the insude of both the boys ears daily just in case we ever need to medicate them :wink:

I sure hope this isn't the Clostridium again.
 
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daftcat75

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Hmmm, as I recall, when Callie was on transdermal Mirt, we were still only to give it to her every few days, like the pill form, AND, if memory serves, it was also in some sort of syringe that was pre-dosed so we couldn't give her too little or too much. We just put on latex gloves so none went into whoever was rubbing it into her ear, put it on the fingertip of one of the gloves and then started petting her like she loved. Then when she was "into it", would swoop it into her ear and she was none the wiser as we rubbed it in well. (she loved the inside of her ear to be massaged!) Anyway, she never had diarrhea from it. .

Because of that experience, now I make sure I massage the insude of both the boys ears daily just in case we ever need to medicate them :wink:

I sure hope this isn't the Clostridium again.
This is a tube of ointment and the dose is a 1.5 inch ribbon using the ruler on the box. The problem with this is that the thickness of that ribbon can be variable depending on how hard you squeeze the tube and how quickly you lay down your ribbon. It is incredibly inexact. And awkward since Krista doesn't have much more than 1.5 inches of pinna. I have to stick my finger further in her ear than either of us would prefer. I think I gave her too much. When her poops normalize again, I will try a 1 inch ribbon instead.

For now, we're working the anti-diarrhea protocol from here:

She's not having diarrhea anymore. She's still having cow patty soft stools though. But unlike the diarrhea, she squirts it out with little effort or distress and it's one-and-done instead of musical boxes (seal her off in "poop jail" and rotate boxes under her as quickly as I can clean them until she's done.)

My thought is that her colon is still inflamed from the diarrhea yesterday and when that goes down, the colon will absorb water like it's supposed to. To that end, she's getting a loading dose (1/4 pill) of the saccharomyces boulardii every few hours and a spoonful of meat stock as well. Fortunately, she loves both so that's no effort. I will also poach some turkey leg meat and mix with the meat stock for her "bland" (doesn't sound bland to me), easily digestible food if the diarrhea returns.

We travel in two days for two hours' drive and two nights in a hotel for her dentist re-check. I really want her poops to be normal before then.
 
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daftcat75

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Krista was far less blissed than the picture.
26E1D40A-BD2E-4425-A013-F94BEBC45658.jpeg
 

amandag1

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I had Louie on the same mirataz, but no diarrhea...hopefully a one time fluke for krista
 

katiekat89

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Hi, I know this is an old post but did you ever find out if the mirtazapine caused the diarrhea? My cat had a dose at the vet on Wednesday, then had 3 bouts of diarrhea on Thursday and one today. All I am seeing is that it could be a side effect of serotonin syndrome too, so that’s freaking me out.
 
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daftcat75

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Hi, I know this is an old post but did you ever find out if the mirtazapine caused the diarrhea? My cat had a dose at the vet on Wednesday, then had 3 bouts of diarrhea on Thursday and one today. All I am seeing is that it could be a side effect of serotonin syndrome too, so that’s freaking me out.
EDIT: Krista had yet to be diagnosed GI lymphoma. That was the cause of her diarrhea. The mirtazapine just exaggerated it with more food coming in and thus more poorly digested materials coming out.

I don’t want to revive this thread. I’ll respond on your thread.
 
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