Gabapentin side effects in cats- how worried should I be?

[Texarkana]

On Monday, my dear, sweet aged cat had a noise-induced seizure (I knocked over a small table holding the printer, which spooked him and led to a seizure). He does not have a history of seizures. The seizure lasted maybe a minute or two, then he had severe ataxia and stroke-like symptoms.

I rushed him to the vet; his ataxia had mostly resolved by the time the vet saw him. His only lingering symptoms were some slight facial/eye paralysis and excessive drooling. Vet ran some bloodwork and saw nothing remarkable, said the seizure was likely caused by a small stroke or concussion. Vet put him on gabapentin with the plan to bring him back for a follow up next Monday. The facial paralysis and drooling resolved shortly after we left the vet.

Tuesday he was just very drowsy. Wednesday evening, he broke with diarrhea, which is listed as a side effect of gabapentin. Called the vet yesterday, who said to reduce the dose of gabapentin to half a pill. Today the diarrhea persists, and it has gotten more frequent. His appetite seems reduced today whereas he’s otherwise been eating decently. I’ve also seen him lose his balance a few times today (also a listed side effect) and he’s had some yowling moments.

I just got off the phone with the vet and they said I can stop his dosage, but warned me that he may have another seizure. I think I will, though.

What else can I do? I asked them if they thought I should bring him in for fluids, and they were kind of ambivalent. How typical are these type of side effects? Should I be more worried? Is it more going on than just the gabapentin at this point? Any other actions I could be taking? Should I be going elsewhere for a second opinion? (These are all the questions swirling around in my head, not that I expect anyone to have an answer for all of them)

It’s been a bad day; and seeing my poor kitty uncomfortable is not helping.

[DrBeckett]

Just out of curiosity, how much does your cat weigh? What is the dose of the tablet? The smallest dose we carry is 100mg. If you’ve been giving 100 mg tablet, your cat should weigh 10 kg for the upper end dose of 10 mg/kg. That’s a big ass cat.

Sedation is definitely a side effect. Often a desired side effect as we use it as a sedative for mean kitties. Ataxia, the loss of balance, is also very common.

I checked the formulary and it does not mention diarrhea as a side effect, but every medication can act differently on every animal. I would call them and let them know.

While gabapentin was originally an anti-epileptic medication, it’s not my first go-to for seizures. There are so many more effective medications, from pheno to zonisamide, to choose from.

[Texarkana]

@DrBeckett Thanks for your input. These are 50 mg tabs; cat is 13lbs or just under 6kg, so the original dose seems reasonable.

It’s reassuring in a way to hear loss of balance is common, because it is very scary to me considering the cat just had a neuro episode.

The diarrhea has me worried, though. I have told the vet about it twice now and he does not seemed concerned. This is a new vet for me, as I have just moved to this area. I don’t have a good feel for him in terms of how he approaches things. Would you take action for it?

[DrBeckett]

Without having examined your cat or knowing everything your vet knows about the case, I, personally would start on a different anti-seizure med. I really never use gabapentin for seizures because we have so many better meds to use. But that’s just me.

[Texarkana]

@DrBeckett Thanks so much for weighing in! I truly appreciate it.

He has a follow up appointment tomorrow. He had Gabapentin last on Thursday evening (half a pill, 25mg); no seizures, the ataxia seems to be resolved, but the diarrhea and vomiting persists. They are less frequent, though. Hopefully we’ll have a better plan of action for him after tomorrow’s appointment.

Thanks again!

[NoDQhere]

My seizure prone cat is on 1/2 tab of Phenobarb morning and night. It has worked well for him. Before we started the Phenobarb he would have multiple grand mal seizures per day.

[Texarkana]

@NoDQhere Thanks! I was kind of expecting the vet to prescribe phenobarb the first time around, but he didn’t. I don’t know if that will be easier or harder on his system?

I’m hoping the seizure was an isolated incident at this point. Wishful thinking?

[Texarkana]

Just updating: diarrhea finally started to clear up yesterday. He still has soft formed “pudding” feces, but with normal frequency. No more vomiting, and his energy level and demeanor seem to be back to normal.

Follow up at the vet this morning was pretty inconclusive; he looks “fine” and they did run a fecal which was “negative.” (Don’t know what all they tested for, the frustrating part of being in the owner position for me). The plan is to keep him off meds for the time being, but switch him to phenobarb or something else if he develops problems again.

[beowulf]

No advice but just hugs - glad to see some of Kitty’s incontinence is resolving. Jingles for you and kitty going forward!!