How much Phenobarbitone will you prescribe?

RE: How much Phenobarbitone will you prescribe?

Nicola Cole — Thu, 28 Jan 2016 21:40:15 GMT

I use diazepam I/v (up to 3 doses),and I/v phenobarb as first line control, move onto propofol if needed (if head trauma then mannitol etc). I used to use pentobarb I/v (sagatal) and this worked very well but as there is no longer a sterile pentobarb available then as above. I've never used keppra I/v, and use keppra tablets as an add on intermittently rather than long term maintenance.

RE: How much Phenobarbitone will you prescribe?

Busybee — Wed, 27 Jan 2016 19:59:56 GMT

[quote user="Anthony Dennison"]

I've heard of Keppra being used in poorly controlled epileptics only when they have breakout seizures, rather than a daily dose. It potentially lessens the risk of a honeymoon period.

[/quote]

Very useful info - thanks! Have never used it in this way.

RE: How much Phenobarbitone will you prescribe?

grumpyoldman — Wed, 27 Jan 2016 17:07:54 GMT

Apologies "roids" is what I write in the notes, you get used to your own shorthand, I am a locums nightmare.

RE: How much Phenobarbitone will you prescribe?

Evelyn Barbour-Hill — Wed, 27 Jan 2016 15:22:58 GMT

I'm guessing from the context, though I might be wrong, that he meant "a corticosteroid" or maybe he meant "a glucocorticoid", and probably not progesterone.

Why don't people write what they mean? "Steroids" is for ignorant stupid journalists.

RE: How much Phenobarbitone will you prescribe?

Thomas Johnson — Wed, 27 Jan 2016 10:55:28 GMT

[quote user="Hannah Wynne Richards"]

Grumpyoldman. What's GME? and do you mean steroids? I can't work out how to administer tarmac!

[/quote]

Granulomatous Meningoencephalitis, and I, like you, assume he meant 'roids' not 'roads'!

RE: How much Phenobarbitone will you prescribe?

Hannah Wynne Richards — Wed, 27 Jan 2016 10:28:55 GMT

Grumpyoldman. What's GME? and do you mean steroids? I can't work out how to administer tarmac!

Wynne

RE: How much Phenobarbitone will you prescribe?

Dagmar Steele — Wed, 27 Jan 2016 10:08:34 GMT

[quote user="Anthony Dennison"]

I've heard of Keppra being used in poorly controlled epileptics only when they have breakout seizures, rather than a daily dose. It potentially lessens the risk of a honeymoon period.

[/quote]

Exactly what my favorite neurologist told me. She uses Keppra in cluster seizures but tries to wean them off the drug afterwards as the effect seems to lessen when given long term. It's really great for controlling clusters though!

RE: How much Phenobarbitone will you prescribe?

grumpyoldman — Wed, 27 Jan 2016 10:00:12 GMT

I use keppra a lot when recovering head trauma RTA cases .particularly with no previous seizure history ,found it very effective there, probably fewer post recovery long term seizure patients , just a guess or an impression though , also post mylogram , in those with no £££ for MRI/CT and referral but do not want a body bag either. Otherwise I follow the alogarthims in the BSAVA Neurology manual . But also find either Steroid or NSAID with Mannitol seems to reduce swelling and excitotoxicity in those that re-start seizing on recovery. Keppra is also handy to temporarily control partial seizures in dogs with other neurology pending MRI, those suspected GME cases that are twitching and if you give the roads pre scan and the changes disappear, and mass effect cases.

RE: How much Phenobarbitone will you prescribe?

Anthony Dennison — Wed, 27 Jan 2016 09:07:09 GMT

I've heard of Keppra being used in poorly controlled epileptics only when they have breakout seizures, rather than a daily dose. It potentially lessens the risk of a honeymoon period.

RE: How much Phenobarbitone will you prescribe?

Busybee — Tue, 26 Jan 2016 18:43:10 GMT

[quote user="David Mills"]Another reason (/cascade justification) for short term levetiracetam![/quote]

I haven't had much experience at all with using Keppra for epileptics but I thought it was one drug with a 'honeymoon' period, in that it works well for a few weeks then it's effects reduce. How does one manage this if using Keppra in treatment for status? Are you using it to stop the occurring seizures whilst loading pheno etc?

RE: How much Phenobarbitone will you prescribe?

Anthony Todd — Tue, 26 Jan 2016 18:03:04 GMT

[quote user="grumpyoldman"]

the best way to stop refractory seizures is to use propofol as an induction agent , set up a CRI with the induction dose per hour ,for 12 hours ,then halve that at 12 hour intervals while loading your phenobarb/levitiracetam/pexion. Its apparently the best way to maintain BP PaO2 PaCO2 pH, urine output, while avoiding cerebral ischaemia, hypoglycaemia raised ICP and further swelling and inflammation from excitotoxicity.

[/quote]

I just know the "dinosaur" cry will ring out but the pentobarb I/v and a top up only when necessary worked fine and most [if the fits were stoppable] didn't fit again in that episode. We kept them on phenobarb for at least a month, tapered then on and up or down if fitted again.

Easy to manage, worked well, not expensive.

Modern therapy always seems more complicated, more expensive with more ins-and-outs for no special advantage to the patient as far as I can see.

Once again, Arlo's views on seizure management with actual views from a seizure patient would be particularly valuable.

RE: How much Phenobarbitone will you prescribe?

grumpyoldman — Tue, 26 Jan 2016 15:18:13 GMT

RE: How much Phenobarbitone will you prescribe?

Bob Russell — Tue, 26 Jan 2016 15:17:44 GMT

[quote user="Kate Richardson"]

[quote user="Anthony Todd"]

[quote user="Kate Richardson"]I'm sure he does but, and no disrespect to him, it's not valid to this discussion[/quote]

He's got a daughter having seizures and. as far as I recall, phenobarb has been effective. Also he has been able to supply some anecdotal evidence from his daughters experience with a seizure which we can apply to our epileptic patients, viz: the effects during and after a seizure don't seem to be as bad as owners always think they are.

[/quote]

Arlo Guthrie? I agree he may have a view, which he is perfectly entitled to but do you honestly expect him to make clinical comments about treatment in animals which may affect vets decisions? Might as well consult Dr Google!

[/quote]

15 years working at Novartis may not allow specific clinical comments but will have provided a pretty detailed knowledge of the veterinary world!

A little more informed than Dr Google but I am sure Arlo would still not consider himself qualified to decide on medication for a fitting poodle!

Live and work around vets, pick up some of their habits (good and bad!).

RE: How much Phenobarbitone will you prescribe?

Anthony Todd — Tue, 26 Jan 2016 14:35:31 GMT

PS One sensible use of blood levels would be to check that an animal "still fitting" whilst on an adequate dose of barbiturates is actually getting all the tablets prescribed......!!

RE: How much Phenobarbitone will you prescribe?

Glen McIntosh — Tue, 26 Jan 2016 14:24:40 GMT

Yes, you are right, phenobarb will act as an anaesthetic at higher doses, but the difference compared to pentobarbitone is that phenobarb has anti seizure activity at sub-anaesthetic doses, whereas pentobarb has its anti seizure activity at anaesthetic doses.

RE: How much Phenobarbitone will you prescribe?

Anthony Todd — Tue, 26 Jan 2016 14:14:17 GMT

Thanks for the comprehensive reply Glen, I just wish [but I'm well out of it!] that pentobarb by injection was still available...

Always worked quickly and I never had any problems with it at all, although they were in and out of light anaesthesia for as long as necessary in a few cases. Worked well S/C too.

I'm surprised that you say phenobarb isn't an anaesthetic as it is a barbiturate and I thought they were all sort of anaesthetics [in effect] just that some had longer or shorter durations of activity??

RE: How much Phenobarbitone will you prescribe?

Glen McIntosh — Tue, 26 Jan 2016 11:33:54 GMT

[quote user="Anthony Todd"]

Glen, I used to give pentobarb gradually, as with an anaesthetic, to effect, ie when the fitting stops, but you say a bolus.

Why don't you just give enough, slowly, to stop the fit?

Do you find diazepam ever stops fits?

[/quote]

Yes, I used pentobarb like that back in the day. But we administered to effect because it is, essentially, an anaesthetic, and we were, in effect, anaesthetising these animals.

Phenobarb is not an anaesthetic. Further, you can't really give it to effect because it takes around 30 mins for it to have any anti seizure activity.

So I am not using it to stop a seizure that is currently occurring, I am using it to try and prevent seizures recurring after I have stopped them first, using some other drug - usually diazepam.

I use diazepam as a first line control of seizure activity. Yes, I find that diazepam does stop seizures in most cases, but sometimes it takes 2 or 3 boluses. But it only controls them for a short time, so if the dog presented in status or having cluster seizures, and there is a high likelihood of seizure recurrence, and I have ruled out the straight forward extra cranial causes of seizures (e.g. hypoglycaemia, hypernatraemia, HE etc) then I will usually give them a phenobarb iv bolus (slow iv) to try and achieve longer term control.

RE: How much Phenobarbitone will you prescribe?

Anthony Todd — Tue, 26 Jan 2016 11:10:18 GMT

[quote user="Glen McIntosh"]over phenobarb iv bolus in most cases.[/quote]

Glen, I used to give pentobarb gradually, as with an anaesthetic, to effect, ie when the fitting stops, but you say a bolus.

Why don't you just give enough, slowly, to stop the fit?

Do you find diazepam ever stops fits?

RE: How much Phenobarbitone will you prescribe?

Glen McIntosh — Tue, 26 Jan 2016 11:01:48 GMT

[quote user="David Mills"]Of course phenobarb injection is also not licensed. And it knocks them out for a few days. Another reason (/cascade justification) for short term levetiracetam![/quote]

This is not my experience.

I use injectable phenobarb fairly regularly (at least once or twice a week) as part of initial stabilisation of status and cluster seizure cases presenting as emergencies. I use the BSAVA formulary dose of 10 - 12 mg/kg iv for animals naive to phenobarb and 5-6mg/kg iv for those already on it. (Diazepam is usually given first for immediate short term control of seizures).

This dose seems to stop seizures pretty well in most cases, usually for at least 12 hours. There is some sedation but fairly mild, and these animals are usually pretty responsive, certainly not knocked out. The only exception appears to be animals with severe underlying intracranial disease, and these will often be close to stuporous for some hours, however I think that in these cases it is often the disease process causing (or at least contributing to) this, rather than the phenobarb bolus alone.

Levetiracetam iv is also an excellent drug for this type of case but cost tends to limit its use in many cases.

However I don't see any great benefits to its use in the emergency treatment of seizures, over phenobarb iv bolus in most cases. It may be a little less sedating than phenobarb, but it is hard to see a difference in most cases since phenobarb isn't that heavily sedating anyway, in most cases, in my experience.

RE: How much Phenobarbitone will you prescribe?

Anthony Todd — Tue, 26 Jan 2016 10:57:10 GMT

[quote user="David Mills"]Of course phenobarb injection is also not licensed. And it knocks them out for a few days. Another reason (/cascade justification) for short term levetiracetam![/quote]

Usually, as I recall, the first contact with an epileptic dog is when it is having, or just had, a fit.

Back in the day I found the only thing that would reliably stop a fit was I/V pentobarbitone to effect, Sagatal [M&B, long gone] was the anaesthetic and Euthatal was just that.

I found Diazapam ineffective sometimes and with a duration of a couple of hours if it did stop the fit.

Sounds like there are better drugs now.

What is the consensus of opinion?

RE: How much Phenobarbitone will you prescribe?

David Mills — Tue, 26 Jan 2016 10:01:45 GMT

[quote user="Thomas Johnson"]

[quote user="Anthony Dennison"]

Giving i/v phenobarb also get animals reaching a steady state quicker (hours rather than days), if I remember correctly

[/quote]

Or you can give an oral loading dose, but both tend to be very sedative.

[/quote]

Of course phenobarb injection is also not licensed. And it knocks them out for a few days. Another reason (/cascade justification) for short term levetiracetam!

RE: How much Phenobarbitone will you prescribe?

Arlo Guthrie — Tue, 26 Jan 2016 09:50:52 GMT

Interesting point.

Kate Richardson my first thought reading your post was: 'she's right, my observations are absolutely worthless".

Actually, in the case of epilepsy, I'd argue that yours (everyone's) are too!

Largely because the symptoms are SO variable over time, that ANY personal observation, whether by an owner, doctor or vet is largely meaningless.

Doctors don't properly understand what causes seizures, or why a patient can have one seizure this week, none the next, and six the next. So how on earth are you supposed to conclude that in a given patient, it was a drug that caused a reduction in seizures, and not just the naturally cyclical nature of the condition?

Honestly, there have been many times over the last decade that if I didn't have such a sceptical outlook, I would have not only used homeopathy, but sworn blind that it was effective! As it is, we've used about a dozen drugs, and I'd be hard pushed to tell you anything remotely interesting about any of them, with the exception of phenobarbital, where we noticed such a dramatic correlation with a reduction in seizures that it was impossible to ignore.

That said, we're now down to almost half the dose that she has been on for some time, with apparently no return to the severe clusters of old. So did we misinterpret what we thought we saw when we were putting the drug up?

Frankly, the ONLY thing I place any trust in is trials.

The other reason my observations are pretty useless is that epilepsy isn't really a condition in and of itself, but a clinical symptom of one of many possible underlying conditions. In my daughter's case, an SNC1A gene missense mutation. In others it's caused by cerebrovascular problems. Or by brain injury. Or it's idiopathic. (sorry, don't mean to teach granny to suck eggs here, just explaining my thinking).

Drugs and treatment vary quite considerably, patient by patient. In my daughter's case, for example, some AED's are known to make the seizures worse (such as lamotrigine and carbamazepine).

So again, my comments/opinion are of limited value because it's a very specific disease she has, and I'm not even sure whether an SNC1a mutation has even been identified in animals.

All in all, I think the best one can ever say is that: in trials, x% of patients experienced an improvement of y%. If a patient takes a drug and they improve, it's possible they are one of the %age that respond. If 90% responded in trials, balance of probability says that's what is causing the improvement. If only 50% responded in trials, it's equally possible that they just experienced regression to the mean.

RE: How much Phenobarbitone will you prescribe?

Anthony Todd — Mon, 25 Jan 2016 23:04:14 GMT

[quote user="Kate Richardson"]Arlo Guthrie? I agree he may have a view, which he is perfectly entitled to but do you honestly expect him to make clinical comments about treatment in animals which may affect vets decisions? Might as well consult Dr Google! [/quote]

As most humans are animals, and most drugs are tested on animals, then humans, then used clinically on animals and as he is involved in an important study on drugs and epilepsy and as he has a daughter with epilepsy who can, and has, told us, through him, what it apparently feels like to have a seizure which no animal has ever been able to do then I do think Arlo can make any comment he likes to make.

Most of his comments, for me anyway, are highly relevant and rank as clinical observations on another species of animal so he can continue to make as many as he likes.

RE: How much Phenobarbitone will you prescribe?

Kate Richardson — Mon, 25 Jan 2016 20:40:13 GMT

[quote user="Anthony Todd"]

[quote user="Kate Richardson"]I'm sure he does but, and no disrespect to him, it's not valid to this discussion[/quote]

[/quote]

RE: How much Phenobarbitone will you prescribe?

Anthony Todd — Mon, 25 Jan 2016 19:48:54 GMT

[quote user="Kate Richardson"]I'm sure he does but, and no disrespect to him, it's not valid to this discussion[/quote]