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Phenobarbital side effects--how long?

My dog (shepherd/husky mix, 73 pounds, 12 years old) began to have grand mal seizures last week. He had two seizures, one on Sunday and one on Monday, at almost exactly the same time in the evening. After the second seizure, the vet put him on phenobarbital (97 mg/2x per day).

He's been on it for five days now and is still pretty out of it. He is extremely lethargic (sleeps most of the day), has coordination problems, and weakness in his hind end. He walks veeery slowly. He's also extremely hungry and thirsty. I've read that all of these are possible phenobarbital side effects. How long do these usually last before the dog gets used to the medication? I'm hoping that these are not signs that something else is wrong, though I am aware of the possibilities.
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Avatar universal
Hello my name is Richie ive had a trying few weeks I took my dog to the vet to be checked out because he was in pain and vomiting,,,they seen my dog they took blood and uranian samples they told me my dog was fine and that he was just progressively going blind well I paid them over a hundred and something dollars for these test for them to call me back 72 hours later asking for a uraine sample because someone miss placed it or threw it away now my question is with that blood test would they have know my dog was diabetic
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Smokella13 ... It depends on the type of blood test undertaken. Vets tend to complete a standard test, but that may not include the relevant checks of things like blood glucose, which is required for identifying diabetes. Tony
Hi.  My name is Tracy and I have a 125 pound,11 year old golden retriever.  He started seizing about once a month for the last year.  We stopped using cleaning products, heart worm med, etc. to prevent triggers.  last Friday night he had 9 seizure's in a row.  He was started on 6 grain of pb twice a day. After 24 hours his hind legs were paralyzed and he hasn't been able to walk.  I've convinced the vet that he was started on too high a dosage and he is now down to 2 grain twice a day.  Shadow try's to get up but ends up dragging his hind quarters behind him.  any idea when this side affect will go away and he will walk again? He was weak in the back end anyway.  This can't be good for keeping up his muscle tone.
Avatar universal
Hello,
I have a 14 yr German shepherd mix and she has currently been suffering from seizures. Her first seizure commenced second week of June and she has had some twice a week for less than 1 minute. The recent one she had was longer about 20 min. I was not home but my mom told me it was a long one. I started her with phenobarbital just days ago and she now has problems lifting herself up from the floor and seems very clumsy. Three weeks before I took her to the vet because she had a seizure, my dog had visited the vet to get heart worm test and I wanted them to take a sample of a lump on her chest that has been growing rapidly just recently. Could the cause of the seizure be because i had her take sample of fluid from that lump on her chest? She wasnt showing any problems before that test. The test result for lump came inaccurate because they didnt get enough sample, even though they took three samples of the liquid inside the lump which had some blood. I will like to know also how long do the side effects last until she is normal again?
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Hi. I would suggest identifying the nature of the lump is the first priority and, if it is cancerous, whether it has spread to other parts of the body. Seizures can be caused by many things, including cancer, but also age is relevant too. If there is a primary condition causing the seizures, then that needs to be treated, otherwise the seizures will gradually get worse.

Phenobarbital does cause a side-effect drunk-like state in most dogs. This should disappear once the therapeutic level has been found - and that involves getting blood tests done by the vet at least once a month for the next 3 months and until the appropriate dose of phenobarbital has been identified.

Tony
1916673 tn?1420233270
Hi. To receive accurate results, dogs need to be starved of all food for at least 8 hours prior to a liver enzyme test. This does vary depending on the laboratory used for the testing, so always follow your vet's advice. The phenobarbital test ordinarily needs dogs to starve for at least 12 hours.

Tony
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Avatar universal
At 11 my pug started having seizures in conjunction with high blood pressure and hypertension. Our vet put her on Pheno and she was completely out of it, could barely walk or do anything. So we lowered the dose but then she started with the seizures again. We had no choice but to bring dose back up. After about 2 weeks the lethargy started to wear away but she became hungry and thirsty all of the time and would bark and cry all day and all night. Also lots of Potty accidents bc of increased water and food. We contemplated taking her off bc she was unbearable to be around and not funny little self but she was seizure free. Feeding her a third meal of chicken and pumpkin helped a little but still relentless for food. Finally ... After 2 months, she is getting back to her old self. She is still hungrier and thirstier than she ever was but she's mostly back to her old self. So point of my story is... Stick with it, don't give up on your dog... They will come around, even after two months of insanity. Make sure you get blood tests though to check Pheno levels and it can be dangerous at too high of a level.
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Hello, thank you so much for posting this information. I'm glad to read that your sweet dog finally got back to normal. My dog Pearl had her initial dose of phenobarbital yesterday and spent the night at the vet. We took her home today and when she's not sleeping, she's pacing around the house and crying. We even gave her Valium (vet prescribed.) It's nice to know that one day it will stop. It's 4 in the morning, we need some sleep!
Avatar universal
Hi,
My Labrador, Buddy is on phenobarbital and is due his blood tests today. His own Vet requested that we take him in starved. The plan was for him to have his blood taken, feed him and then have some more blood taken 2 hours later.
Unfortunately my husband forgot to omit feeding him this morning so it looks like we'll have to cancel his appointment.
My question is;
Is it necessary to starve dogs to have their liver function test and phenobarbital therapeutic levels checked?
It' just that when he used to see the his neurologist for check ups they never asked us to starve him before his blood tests
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Avatar universal
I'm an owner of a newly diagnosed Epileptic dog who is also Epileptic! I take Pregabalin and Keppra myself after trying several other drugs with no luck. The Gizlet is on the standard Phenobarbitol (was literally started on it yesterday) but I know how well Keppra works for me so it's in the back of my mind in case it can be used as an additional drug.

Keppra is a unique Epilepsy medication as it doesn't work like any of the other drugs used for treatment. In fact medical researchers aren't even sure how it works, but it does, especially in cases where other medicines aren't helping. This is most likely due to it's unique chemical structure and method of effect on the neurons in the brain. You're quite right, it's a drug that is well worth keeping in mind if the standard meds aren't working or aren't consistently working.

I'm so sorry to hear you lost your furbaby, it's inevitable that they will die but no less devastating when they do. The Gizlet is currently 8 years old and is a Yorkie so hopefully we have many years with him left, but I do worry about him developing a brain tumour or simply dying in his sleep, both of which we humans with Epilepsy are far more at risk for too.
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Avatar universal
I'm an owner of a newly diagnosed Epileptic dog who is also Epileptic! I take Pregabalin and Keppra myself after trying several other drugs with no luck. The Gizlet is on the standard Phenobarbitol (was literally started on it yesterday) but I know how well Keppra works for me so it's in the back of my mind in case it can be used as an additional drug.

Keppra is a unique Epilepsy medication as it doesn't work like any of the other drugs used for treatment. In fact medical researchers aren't even sure how it works, but it does, especially in cases where other medicines aren't helping. This is most likely due to it's unique chemical structure and method of effect on the neurons in the brain. You're quite right, it's a drug that is well worth keeping in mind if the standard meds aren't working or aren't consistently working.

I'm so sorry to hear you lost your furbaby, it's inevitable that they will die but no less devastating when they do. The Gizlet is currently 8 years old and is a Yorkie so hopefully we have many years with him left, but I do worry about him developing a brain tumour or simply dying in his sleep, both of which we humans with Epilepsy are far more at risk for too.
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1916673 tn?1420233270
Hi. Yes, she will come out of this phase. It may take several weeks, but eventually, the phenobaribital will "kick in" and the side effects will dissipate. The important thing is to make sure you give the tablets each 12 hours (presumably that's what has been prescribed) and don't miss a dose. The drunk-like state will subside, eventually. It's also important to have regular blood checks, as that's the only way of working out (by trial and error) what the correct dose needs to be. Tests should be done at least monthly for the first 6 months and then quarterly and then six monthly later on. If the phenobarbital fails to have the desired effect (after about a month or so) then there are other drugs that should be tried as an alternative.

Tony
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1916673 tn?1420233270
Sorry I didn't get to you sooner. I am very sympathetic about your circumstances and situation. Phenobarbital is a good medicine for seizures so stick with it through the initial phase of side effects and "settling". It takes a while to get things under good control, but it's worth it. You don't know whether there's a tumour or not, though it is possible. It would be expensive to have the scans needed to find out for certain. The initial phase of phenobarbital does cause a "drunk like" state, but that will pass with time.

Tony
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Avatar universal
I have a hound/pointer mix.  Justice is just shy of 12 years old.  She has been having 4 to 5 seizures per year but they never put her on any medication because they didn't think they were frequent or severe enough to warrant that.  In January, she has a bad seizure and hasn't been the same since then.  Within a couple weeks, she starting pacing, panting and shaking.  I took her to the vet and they did some blood tests that all came back normal.  They gave her two shots of valium with no relief.  I gave her half of a tranquilizer when we got home and she finally calmed down.  These "episodes" continued every few days.  I took her to a neurologist and they did a liver function test and it came back normal.  That same day, she had a very, very bad seizure and I called the neurologist and he put her on phenobarbital.  Its only been a week, but I feel so bad because she is walking (tipping and falling) in a drug induced stupor all the time.  She just isn't the same dog anymore.  Will she come out of this phase?  
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Avatar universal
my 11 year old dog has starting taking seizces and been put on steroids and pb 1 and a half morning and night hes always hungrey and at night barks all the time pdsa said he might have a brain tumour hes went from a great dog to one a don't regonise he paces the room panting all the time a don't have the money for private vet and pdsa are limited in what they do can u give me any tips to help kenzo my dog vet wants to put him to sleep what do you advice me am at my wits end
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Avatar universal
my 11 year old dog has starting taking seizces and been put on steroids and pb 1 and a half morning and night hes always hungrey and at night barks all the time pdsa said he might have a brain tumour hes went from a great dog to one a don't regonise he paces the room panting all the time a don't have the money for private vet and pdsa are limited in what they do can u give me any tips to help kenzo my dog vet wants to put him to sleep what do you advice me am at my wits end
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Avatar universal
hi,  new to the page BUT please stop the Rimadyl
all of those related drugs are biggies for liver kidney fails in older arthritic dogs
the exact ones they give them to
precvicox is THE worst Ive known too many aged dogs go down within a few days of using it.
other names vary but usually an X in it = for the  coX2 inhibitors
if you really must? meloxicam liquid is far gentler and you can usually halve the dosage and still get good relief
ONLY ever use them for a few days at most.

and if theyre on the phenobarb etc its a double whammy, liver assault wise

Ive used the injectable Pentosan aka cartrophen a series of 4 injections over a month they are  close to miraculous in the results of bad arthritis or joint issues. and safe.

and I am here because my 62kg great dane/staghound had his frst  seizure while asleep next to me on 26th dec 2016
then a follow up jan 31st
both during day in what i wouldnt have thought deep sleep cycle
the first one he was going blue due to tongue in throat
my idiocy  cost me one severely damaged finger and stitches and broken bone;-(
yeah tried to move his tongue
he came round as I did and chomp!
no one else Ive noticed mentions any aggression after attacks?
my fellas off kilter disoriented as you would be...but also scared and  likely to growl/snap for a while after.
with his size and weight and 3 others in our pack...its been..hmm.."interesting" shall i say?
today we started an 100mg phenobarb   1/2 2x a day
see how we go

the newest pill on market is supposed to have near no side effects BUT at a cost in AU$ or 170  a month , opposed to 40 for PB  its an option for the well off or small dog owners only really
http://www.ncbi.nlm.nih.gov/pubmed/26330063
brand name is PEXION
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1916673 tn?1420233270
Hi. I think the slower movement is probably a mixture of age and the phenobarbital. At 12, he's entered old age. But on the plus side, it seems the pheno has done the job it's designed to do, which is great. As time goes on, there may be more seizures, so just look out for them - if it happens, the dose may need adjusting or you can add something like potassium bromide which will help boostr the effects of the pheno.

Tony
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Avatar universal
I just wanted to add my experience.  Reading this thread helped me through a rather scary period.

Duncan, Our 12-year-old yellow lab mix had his first grand mal seizure in September.  A horrific experience for my wife and I, who were totally unfamiliar with it.  Next day, we took him to our vet.  His opinion was that since this was the first time, let's take a "wait and see" approach.  Bring him back in if there is another seizure. They did some blood work which showed nothing unusual.  Two weeks later, he had his second seizure at 4am.  We called the vet when they opened at 8.  They said they had an opening at 11am and bring him in then.  At 9am, he had another seizure.  We called again, and they told us to bring him in RIGHT NOW.

Our vet prescribed Phenobarbital (8 mg, twice a day).  However, he felt that if Duncan had epilepsy, it should have shown up earlier in his life, probably by time he was five years old.  It certainly wasn't unheard of for epilepsy to show up this late, but he felt that a brain tumor was probably more likely.  He wanted to know if we'd seen anything unusual about his activity, primarily in motor skills.  Was he having trouble walking in a straight line?  Was he turning his head unusually?  Balance problems?  Anything at all unsymmetrical about his actions?  We hadn't seen anything.  He told us to keep him on the Phenobarbital and bring him back in in a month.

Like everyone else has seen, he was dopey and unsteady for that first week.  After than, his perky demeanor returned, but he was still a little wobbly in the back end.

After a month (and no further seizures), we brought him back in for more blood work, which came back normal.  Our vet felt that the 8 mg dosage didn't need to be adjusted.  Keep him on it and let them know if there were any further seizures or changes.

In December, we brought our dogs in for their yearly physicals.  Our vet said that the lack of any seizures since starting the medications was VERY promising, and if Duncan could make it a few more months, he'd feel confident saying that the problem IS epilepsy and not a brain tumor.

Even now, Duncan is very slightly unsteady on the back end.  He still runs full tilt and terrorizes all the local squirrels, but he doesn't bound up the stairs like he used to, and walks up them slowly and carefully.  Is this due to the medicine?  A permanent result of the seizures?  No idea.  But overall, we're very happy with the outcome.
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1916673 tn?1420233270
Hi. I think there's a lot of room for optimism here, so yes, wait and see and write anything down that you think might be relevant so you have a record of what might have occurred and when. Phenobarbital does take some time to work its way out of the system, so there may still be some effects lingering, which of course could be keeping seizures at bay. If the seizures do return, at least you know what will help control them. In the meantime, I would urge you to try and get the vet to perform a blood pressure check when you go back for the next run of tests.

Tony
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Avatar universal
Hi Tony,

I did speak with the Dr. about the BUN and Creatnine levels after I found her original documents. When I first adopted Sugar her BUN levels were normal. I took her to the vet 2 weeks later for a teeth cleaning. This is when they noticed her BUN levels were in the 40s, never again were they abnormal. Our new vet believes that it could have easily been a dehydration situation or maybe she did't get enough to drink that morning. We are still investigating in Sugar's case, but as of now we are still seizure free (we have not had a seizure since we were on the phenobarbital) and we are now completely off of the phenobarbital. The barking I was originally concerned about has stopped. In fact, it stopped almost completely the day we lowered the pheno dose and she slept through the night completely. Now that we are off the pheno it has stopped completely. She is a completely different dog now. We will go back in for another check up and they are supposed to check everything out again. For now, it is a waiting and prayer game, but we are definitely keep an eye on everything!
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1916673 tn?1420233270
When creatinine is high but BUN is normal, there is a suggestion of dehydration and/or heart issues. There is also the possibility of obstructed urine ducts. Temporary high creatinine can also be caused by a recent meal, so it's always best to check creatinine before the dog eats anything during the day of the test.

Depending on how the test is performed, high blood glucose, vitamin C supplements and certain antibiotics (cephalsporins, particularly) can falsely raise creatinine readings.

I think it's worth keeping an eye on things and having a repeat of all tests (and blood pressure) in a couple of months time, assuming Sugar stays seemingly well during this time.

Tony
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Avatar universal
We got the results for Sugar's blood work and Urinalysis yesterday. He said everything is normal and looks good. From the results she seems to be a perfectly healthy dog, except her creatnine level is just a tad bit above the high end of normal. I did not ask him about the blood pressure. I will have to check with him on that.
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1916673 tn?1420233270
Hi. So far so good. At least your vet is starting to tie things down more and expanding the investigations. The extra blood work and urinalysis will be interesting, so do let me know what they say. I think there is room for cautious optimism. Just one question ... did they do a blood pressure check while you were there?

Tony
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Avatar universal


I really liked this vet! Not just because he gave me what seems to be, for now good news, but because he spent an hour talking with me and giving me hope and options for where we could go from here. I was also 30 minutes late due to being up all night with Sugar and he didn't have a "put out" attitude about it.

He started off saying he was reading through Sugar's medical history and saw that we had a concern with her flea/tick medication and didn't think that was an issue. UNTIL, he saw the ingredients on the packaging and now thinks that it is definitely possible that that could have been the cause for seizures since permethrin is one of the main ingredients.

Secondly, he said that he did not believe we were dealing with kidney failure. He said that there maybe some other issues that could be causing stress on the kidneys, but that she does not seem to have "failure."

Due to her hair loss and discoloring of skin he did a thyroid test. He also did another blood panel and a urinalysis. Hopefully we will get those results back today.

With all of the above in mind, he thinks we have some room to play with the seizure medication. We have decided to wean her off the Phenobarbital for now. We  started yesterday with just giving her half a pill 1 time in the morning (previously it was 1/2 2 times a day) and I am happy to say we had our first full night of sleep since we started the medication. She went to bed around 11pm with no help and woke up about 8am. Hopefully this will be a pattern! He also gave us diazepam to calm her when need be or if she does have a seizure. Obviously, I am holding off on this to see if she will return to her calm nature on her own without the pheno.

The only negative out of the situation was that he thought she may have a thyroid issue and that she maybe even older than we thought. He watched her behavior (pacing with no real destination) and mentioned that we might have a "geriatric" dog on our hands, but I am ok with that as long as she is comfortable.

For now, it is a waiting game and we are praying the seizures do not return without the Phenobarbital. He said he is confident however, that if they do return we can get her back under control.
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1916673 tn?1420233270
Hi. My opinion, for what it's worth, is that this is kidney disease. Probably stage 3. If protein leakage is confirmed, then that's another confirmation. It would also be prudent to get your dog's blood pressure checked (more on that in my article, link given previously). The point is, at this stage, there are lots of things you can do to help prolong life and improve quality of life, but getting a confirmed diagnosis and starting the diet plan and maintaining blood pressure control are crucial.

The seizures are another matter ... it could be this was an acute episode, and a consequence of the flea and tick medication. The problem for your vet now is to find out whether it was acute (and therefore is now not a problem) or whether it is an epileptic type seizure that will get progressively worse without treatment.

Let me know what your new vet advises.

Tony
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Avatar universal
Sugars BUN level upon her first visit (12/28) was 43 and creatine level was 2.1

As of 3/20 her BUN is 23 and creatine is 2.4.

I asked for the recent panel they did, but this is the last one they sent me.

At this point, we have taken her off flea and tick medication completely. I do live in an apartment complex with a lot of dogs and have noticed fleas on her after walking her, but I have narrowed down where they are coming from and keep her from those areas. I truly feel the medicine had SOMETHING to do with her seizures. Albeit, we have only had her for 8 months and I know seizures can come without warning, I just find it odd they came on both times about 2 weeks after the application of the medicine and the reviews.

I know it can be tricky. I have made an appointment with another vet for Saturday, I am sure I already mentioned that. We were taking her to Banfield, who has been great with our other dog, but with a special needs dog I feel she needs a low volume vet that can spend time with her.

As far as hearing and sight, I am glad you brought that up. That is something else I plan to address with the new vet. I do believe her sight is normal, but the hearing is an issue. Before Sugar was on the medicine, when she was sleeping we would have to walk up to her and call her name several times before she heard us. We call her name and there is no response. If there is a loud noise in the room she looks to the total opposite direction to see where it is coming from. Not trying to dismiss any options, but again, this had been the case the whole time.

Thanks for talking through this with me and you have brought up several good points to bring to the vets attention.  I also plan on reading our articles to further educate myself on these conditions.
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1916673 tn?1420233270
Hi again Well, there's a lot there to try and answer ... but I'll do my best.

It is quite wrong for the vet to say you can't tell what stage the kidney failure is at until stage 3 and beyond ... the first blood test (prior to managing the kidney failure diagnosis) is the one to look at, as it is the base result. The levels you need to diagnose the stage is BUN, creatinine and phosphorus. If you have that initial test result, let me know the levels.

The vet is right that virtually all medicines are difficult with kidney failure, because all medicines cause by-product toxins, which further stresses the limited functioning kidneys. Of course, this doesn't mean all medicines should be avoided ... but certainly those that are not crucial to your dog's well-being and good health.

Yes, avoid all flea and tick treatments, unless the risk of your dog catching fleas or ticks are high. FirstSheild is not a treatment that I am very familiar with, though I suspect it falls into the same category as many others that are chemical-pesticide based. You might want to have a read of a piece I did on this subject. You can find it here:

http://www.infobarrel.com/The_Dangers_of_Flea_and_Tick_Treatments_for_Dogs

In fact, both flea and tick treatments - and kidney failure - can cause seizures. Also, the question over the kidney disease is a fair one, because many vets misdiagnose and then treat something that may not be a problem anymore. I would strongly advise your vet undertakes a urinalysis, looking particularly for protein leakage. If there are proteins in the urine, then kidney disease is confirmed. The following article looks at the correct way to diagnose kidney failure - along with various other pieces of information you will probably find useful. That article can be found here:

http://www.infobarrel.com/My_10-Point_Plan_for_Dogs_with_Kidney_Failure

Taking your dog off phenobarbital is a risk, but maybe one worth trying. Dogs can have very serious allergic reactions and acute problems from some flea and tick treatments, and seizures are not uncommon. Taking her off the phenobarbital will test the theory that this was an acute reaction (very possible, considering the other allergic symptoms you have described). There is of course a great danger that the seizures will return, so talk to your vet about this before considering it. Also, don't just stop the drug suddenly, as it needs to be phased out slowly.

The barking remains a puzzle. I am still of the opinion this must be related to anxiety and petit-mal seizures, but it's very hard to be sure without seeing the behaviour first hand. I certainly don't believe it is "down to age", which is a strange comment from a vet. Did the vet check things like hearing and sight? Sometimes, older dogs that are starting to lose some hearing and/or sight, do get afraid or confused and bark as a consequence.

Okay. That's enough from me ... keep me informed.

Tony
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