Phenobarbital Side Effects

[Guest greycrew]

I'm sorry for another topic about Pheno. I have read almost every one I can and most really helped, but I think I may have an extreme situation here and I'm worried. My 10 year old (11 in June) started having seizures in March which I posted about. His bloodwork is perfect. He's had several mild one's since and when they became more frequent my vet gave me phenobarbital which was last Friday. I was planning on starting him on Monday because I had to go out of town overnite Saturday, but he had a seizure while he was sleeping at 7am on Saturday (I know because he sleeps with me). It wasn't bad, but the after effects were bad. He couldn't see - couldn't get off my bed - urinated in the bed while I was trying get him off of it. And it took several hours before he calmed down and stopped pacing and was able to see properly again. I started the phenobarbital that morning. He's on 300 mg - 150 in the AM - 150 in PM. My sister stayed at my house and said on Sunday morning he was wobbly a little and kept crying(he's not a cryer or whiner at all). When I got home Sunday night around 7 pm he was pretty off balance and was still whining a bit. Well yesterday he could barely use his back legs. When I went home for lunch he grabbed his stuffie and tried to play and fell right down - his back legs splaying out - and started crying. I had to help him up and help him outside for potty break. I called vet and they said to halve his dosage. I did not give him any last night and this morning I gave him half 75mg, but he is still unable to get around well on his own and all he wants to do is lay down. And when he does lay down he has no control over his back legs and I have to fix them for him to make him comfortable. Finally my question... I read in other posts that this only temporary - did anyone's grey have side effects this bad and can it possibly go away? I'm afraid he's going to get hurt. I'm not sure if I should stop the pheno and try another med or keep with half the doseage and see what happens. I'll be checking on him at lunch time...

[Guest CampWhippet]

We have a seizure whippet who gets her pills three times a day so she does not have to take as much in the two-dose plan. Is that a possibility for you? We do 6am, 2pm and 10pm.

 

150 mg is a very high initial dose but I am not second guessing your vet's treatment plan, just saying. I do know that giving that much is going to really knock a dog for a loop though and that is certainly your experience. He will begin to tolerate that better but it is going to take a while.

 

I'm interested in hearing what the dosages for others on the board are who have similar-sized greyhounds, particularly what the initial dosage was and how it was increased as the seizures returned over time. You describe the seizures as mild and it sounds like not that frequent. These two facts are used to determine the level of initial dose and all treatments plans should be for giving the smallest dose possible to control the seizures. You mention halving the dosage and I say talk to your vet today about that today and i bet you will get approval.

 

Our dog also takes two other meds BTW. Keppra and pottasium bromide.

[Guest greycrew]

Oh yes and Tone weighs 84 lbs. I should have mentioned that...

Edited May 10, 2011 by greycrew

[Guest BrianRke]

My parents 65lb, 14yo dog has been taking pheno for the past few years. He exhibits the EXACT same symptoms you described above. He takes 45mg 3x/day. The dosage you are using seems quite high to me too. I would probably ask for a second opinion.

[Guest greycrew]

I just called the vet to make sure dosage was correct and they said yes and that something else may be going on and I can bring him in. I know it's the meds, though. Brian, does your parents dog still have these issues or did they go away in time?

[galgomum]

I just called the vet to make sure dosage was correct and they said yes and that something else may be going on and I can bring him in. I know it's the meds, though. Brian, does your parents dog still have these issues or did they go away in time?

 

Think it is wise to bring him in.

As I read it, something really changed before you got him on the Pheno.

He had a really hard time recovering, which also happened to our Johnny, the vet wanted to see him after that.

 

So I would bring him in anyway.

[Guest greybookends]

Several years ago I had a GSD who had seizures. He waz a big boy over 80#. When they started him on the pheno they started him on a dose that was based on his weight. I was not happy with the way he acted on it when I first started him and when it did not improve after a few days I was very concerned and called the vet. The dose was to high. I spent 3 days on the floor with him bringing him down off of the over dose. A third of the original dose was all that was needed to keep him seizure free. I hope your baby is ok.

[Guest CampWhippet]

...... A third of the original dose was all that was needed to keep him seizure free.....

 

This is what I am thinking in this case too.

[Guest BrianRke]

I just called the vet to make sure dosage was correct and they said yes and that something else may be going on and I can bring him in. I know it's the meds, though. Brian, does your parents dog still have these issues or did they go away in time?

He still has them unfortunately, after 4 years

[Guest d0ggiem0mma]

Loading doses for Phenobarb can be quite high. The dosage you are using sounds absolutely reasonable for loading. Lethargy is the most common side effect of the drug and it sounds like your pup is pretty knocked out. Most vets recommend or even require 24-48 hours in the hospital during loading as the dogs can get quite lethargic but they do improve.

 

I'd say to take him in and get a neuro exam on him. If he never normalized after the seizure, it could be more than drug side-effects.

[TheFullHouse]

A greyhound who starts having seizures at the age of 10 could possibly having something more going on neurologically. I'd have him checked out. Most dogs who develop seizures do so between the ages of 3 - 5 years of age. As for the side effects of the pheno, yes, it can cause dogs to be off balance. They can basically walk around drunk, have little coordination and splay their back legs, usually for up to 2 to 3 weeks before the body adjusts. In most cases the body does adjust. Even at that they can have a little hind end weakness the entire time they're on it. My Saint takes 600 mg. a day, 300 a.m. and 300 p.m. and he does have a little hind end weakness but it isn't so bad that they can't run and play in the back yard. He's been on it for over 6 years now and is doing fine.

 

If he were my greyhound, I would have him checked out neurologically because this sounds like it could be something more than just the medication, especially at his age.

[Guest greycrew]

He was not acting like this before the Pheno. I mean after the seizure he kept pacing, but was not falling down. I've never seen him act this way in the 8+ years he's been with me. When I took him for testing after the seizures began he did blood work, but did not think at his age he should go through the neurolical testing and I agreed. I just checked on him and he made it outside on his own. He had a bit of a hard time getting back up the porch steps but did it on his own. He's still a bit wobbly. If no improvement after work I'll take him to vet. they are open late tonight. Thanks everyone for you input. I don't have to tell you all how much it helps.

Edited May 10, 2011 by greycrew

[RaineysMom]

I agree, that seems like a very high dose. Rainey was 62 lbs and on 60mg 2 x day! She initially was wobbly (that lasted like 3 days?) but did have hind-end weakness here and there after that but not nearly as bad as yours. Guessing it's from the big dose....the neurologist Rainey saw chose not to do the load thing, and pheno seemed to keep the seizures at bay (along with Keppra and Zonisamide too) but we had other (worse) issues going on with the pheno...

 

*Most* of the time when a greyhound starts having seizures at 10 (like Rainey) it's from a brain tumor .... but we had an MRI done back in October of 2010 and nothing was there. We were going to have another done on 3/9/11 but instead made the painful decision to let her go on 3/8. Her neurologist said that he fully expected to see severe loss of brain tissue (rather than a tumor) in Rainey, had we gone through with it. She was having more and more mental issues (that until now I didn't realize were as bad as they really were, when it happens slowly you just "take it") that led him to believe that was the case. We'll never really know. But I would recommend taking him to see a neurologist if there's one you can take him to.

 

sending hugs. Seizures SUCK.

[Guest LindsaySF]

That's a very high starting dose for the Pheno. He likely needs half that dose, maybe less, especially if his seizures are minor. Unlike KBr, you don't need a "loading dose" really for Pheno, it gets into the bloodstream pretty quickly and has a short half-life.

 

The rear-end issues are called ataxia, and they are common when first starting meds like Pheno. If he can't walk though and is falling, then the dosage needs to be decreased. You want him on the lowest dosage possible that still provides good seizure control.

 

I do agree with Judy though, that idiopathic epilepsy usually hits between the ages of 3-5. A 10 year-old dog that starts having seizures usually points to some other underlying condition that's causing them.

 

 

 

~Lindsay~

[Guest greycrew]

My vet said to give him half the dosage which is what I'm doing today, and tomorrow I'm going to drop it down to 1/3 rd. I'll give him 50mg in the am, 50mg pm. I'm thinking it's not good to stop the meds completely so I'll try it this way. I feel so bad for him. He doesn't even want to stand up to eat. I'm hand feeding him homemade treats and his food so he doesn't have to stand up. It's stinks. I want my dog back!

[RaineysMom]

My vet said to give him half the dosage which is what I'm doing today, and tomorrow I'm going to drop it down to 1/3 rd. I'll give him 50mg in the am, 50mg pm. I'm thinking it's not good to stop the meds completely so I'll try it this way. I feel so bad for him. He doesn't even want to stand up to eat. I'm hand feeding him homemade treats and his food so he doesn't have to stand up. It's stinks. I want my dog back!

 

you definitely want to wean them off, not stop completely. With Rainey, the first time we put her on it we had to take her off...she got her first dose on Monday night, 8/30, then we saw the neurologist that Thursday (9/2) and he had us continue to give the full dose (60mg 2 x day) until 9/5, then we went to 1 pill 1 x day, then stopped completely on 9/10 (not sure why we kept giving the 2 pills until 9/5, but he said to). You may want to check with the vet before doing any more decreasing?

 

I really hope by decreasing it he'll get better quickly, you must be worried sick. Has he improved at all since you started decreasing? (I know you just started).

[kamsmom]

My vet said to give him half the dosage which is what I'm doing today, and tomorrow I'm going to drop it down to 1/3 rd. I'll give him 50mg in the am, 50mg pm. I'm thinking it's not good to stop the meds completely so I'll try it this way. I feel so bad for him. He doesn't even want to stand up to eat. I'm hand feeding him homemade treats and his food so he doesn't have to stand up. It's stinks. I want my dog back!

 

 

Steak is now up to 300mgs a day (may be like 320 or something I can't remember the exact dosage but I know it's around 300). He is not the same dog he was I miss him. He is still a very sweet, gentle soul but is different since we started medicating. We have been on the pheno now almost two months and he is still seizing about every two weeks. His are gran mal seizures every time. The most recent was just last week. He takes about 2 hours to settle after them. He is much, much more vocal and whiney now as well. He is always hungry and never seems to really relax any more. I often have had thoughts of whether he is better off with or without the meds. The vet and I have agreed to one more increase in the meds and to add potassium bromide and then we will do an MRI...

[Guest greycrew]

I really hope by decreasing it he'll get better quickly, you must be worried sick. Has he improved at all since you started decreasing? (I know you just started).

 

He was on 300mg Saturday and Sunday. Monday I only gave him 150mg in the morning and he was really bad all day long and even this morning. I did not give any last night. I gave him 75mg this morning and he's really out of it, but getting around on his own at least. My italian greyhound is afraid of him. As soon as he starts wobbling around the iggy runs upstairs and shakes in the bed. He's so funny.

[RaineysMom]

My vet said to give him half the dosage which is what I'm doing today, and tomorrow I'm going to drop it down to 1/3 rd. I'll give him 50mg in the am, 50mg pm. I'm thinking it's not good to stop the meds completely so I'll try it this way. I feel so bad for him. He doesn't even want to stand up to eat. I'm hand feeding him homemade treats and his food so he doesn't have to stand up. It's stinks. I want my dog back!

 

 

Steak is now up to 300mgs a day (may be like 320 or something I can't remember the exact dosage but I know it's around 300). He is not the same dog he was I miss him. He is still a very sweet, gentle soul but is different since we started medicating. We have been on the pheno now almost two months and he is still seizing about every two weeks. His are gran mal seizures every time. The most recent was just last week. He takes about 2 hours to settle after them. He is much, much more vocal and whiney now as well. He is always hungry and never seems to really relax any more. I often have had thoughts of whether he is better off with or without the meds. The vet and I have agreed to one more increase in the meds and to add potassium bromide and then we will do an MRI...

 

Beth, sorry to hear Steak is still having seizures :( I really feel for you. And how he's acting sounds a LOT like Rainey -- "never seems to relax anymore" -- that's a perfect way to have described her behaivor. She used to sleep most (if not all!) the time but after being on the pheno, she would MAYBE sleep 1.5 hours after I fed her at 1:15pm, then not sleep again until we went to bed -- and most times she was up during the night. She was EXTREMELY whiney and vocal too, but at the end was literally either screaming, rooing or barking non-stop for hours. We thought the same thing, would she be better off having the seizures! she was so not like herself anymore, either (the severe aggression was the really bad part ) but with her there was something very, very wrong with her brain.

 

sorry, not trying to hijack!!!

[Guest greycrew]

Steak is now up to 300mgs a day (may be like 320 or something I can't remember the exact dosage but I know it's around 300). He is not the same dog he was I miss him.

 

I think this might be the worst part of. Tone just looks sad. It's horrible. He still kisses me and wants to be right next to me, but I know he's confused and suffering. It's really hard to take.

 

He also has been waking up in the night several times panting like crazy. I even put the air conditioner on in the middle of the night last night thinking he was too hot. But, it wasn't hot in my room. I wish I just be next to him 24/7!

 

Thanks everyone for your input. It means the world to me. I will keep you updated on his progress.

[Guest FullMetalFrank]

I hope reducing the dosage works... I don't have any experience with pheno use on my own dogs, but several of my clients at the kennel are on it and they all tolerate it differently; from the best being a big lab fellow who acts pretty much like a normal lab, to the worst being a kitty who sits in her kennel and shivers and can't hardly stand up

[hikinghounds]

That dose sounds really high. My 85 lb boy was taking 60 mg twice a day and that was really knocking him out, tired and loopy. As I reduced it got better. Greyhounds can be more sensitive to medicines and might need lower doses than other dogs. But 125 still sounds too high. You might want to see a neurologist, they might be able to better diagnose what's going on.

 

I hope things improve!

[Batmom]

I would get him back to the vet and probably want a 2nd opinion. Some of your description sounds more like a stroke than a seizure. Sending prayers and gentle hugs for you and your boy.

[Guest jackjack]

A greyhound who starts having seizures at the age of 10 could possibly having something more going on neurologically. I'd have him checked out. Most dogs who develop seizures do so between the ages of 3 - 5 years of age. As for the side effects of the pheno, yes, it can cause dogs to be off balance. They can basically walk around drunk, have little coordination and splay their back legs, usually for up to 2 to 3 weeks before the body adjusts. In most cases the body does adjust. Even at that they can have a little hind end weakness the entire time they're on it. My Saint takes 600 mg. a day, 300 a.m. and 300 p.m. and he does have a little hind end weakness but it isn't so bad that they can't run and play in the back yard. He's been on it for over 6 years now and is doing fine.

 

If he were my greyhound, I would have him checked out neurologically because this sounds like it could be something more than just the medication, especially at his age.

 

Sad, but very true. We just lost our dog Stuey, who also started having seizures at (nearly) 10 yrs. Stu had his first seizure 3/10/11. Within 36 hours he would have four more. His last seizure actually happened at the vet and was quite serious. Like your boy, Stuey's bloodwork was also fine, so he was started on pheno (and a combination of pheno and KBr about a month later). In Stuey's case (as you and others have mentioned), he was not the same dog after being medicated, but DH and I remained hopeful. Unfortunately, our optimism didn't last long. It wasn't long before other symptoms started to appear, and we realized that we were likely dealing with something more than just epilepsy. Within a month of his first seizure, it was obvious that he had lost some vision in his right eye. He was no longer able to respond to commands, and he started walking around in circles (always circling to the left). Pheno had made Stuey hungrier and thirstier, and we had tried to accomodate his increased need to relieve himself. He had plenty of accidents in the house, but it wasn't anything DH and I couldn't handle. I was ready to admit to myself that something was very wrong when, after being in the yard for long periods of time, Stuey would come into the house and immediately pee (or have a bowel movement). It was as if he didn't know where he was supposed to go anymore (if that makes sense). It also got to the point where he couldn't seem to find his way back to the house after being let out (which was not the case when he first started on pheno). In Stuey's last week, he also seemed to have problems seeing out of his "good" eye. He could no longer navigate his way around our home, and had to be guided to his bed, to the door to go out, and to his food dish. His circling (always in the same direction)also became more intense. If Stuey was awake he was walking in circles. If he was outside, he was walking around in circles. While he was eating, he would take breaks so he could walk in circles (and proceed to forget what he was doing and where his food dish was). The best way I can describe it is OCD.

 

Sorry for the drawn out post. The only reason I'm mentioning all of this is that, in the event you might also be dealing with something more serious than epilepsy (like a brain tumor), other symptoms will likely present themselves. Dopey, clumsy behaviour and muscle weakness are common side effect of pheno. These should subside (to some degree) once your pup gets used to his dose, or once his dose is lowered. Other symptoms (like vision loss, constant circling and forgetting where he is supposed to relieve himself in Stuey's case) could mean something more sinister is brewing. Our story didn't have a happy ending, but I'm sending you tons of hugs because DH and I have been there. My sincere hope is that some simple alterations in his meds is all your boy needs to be a happy, healthy hound.

 

HUGS!

[Guest greycrew]

Thank you JackJack for your post as well. I know it's not normal for Tone to be having seizures at this stage of his life. But, I don't want to put him through all of the testing. He had a dental in December and I swear a different dog came out of that office at the end of that day. He was so thin and scared and tired. I swore I wouldn't do anything that stressful to him again. So, I'm doing the best I can trying to control the seizures. I haven't slept a whole night since his first one back in March. I'm a mess and sick myself as a result, but trying to be strong for him. He's my heart dog. I wasn't expecting him to have these effects from the pheno. I thought it would help. I'm hoping it gets better and I have him much longer, but I know it may be something much worse.

I just called vet again becuase I'm scaring myself reading on the web that you can't just lower pheno dosages, but he assured me that I can stop totally if I wanted to. In fact, he said then I will know if the behavior is from the meds or something else.