Use by dates

Re: Use by dates

Colin Cameron — Thu, 02 Dec 2010 13:07:31 GMT

If you give enough it certainly stops the seizures!

Re: Use by dates

Mark Hedberg — Tue, 09 Nov 2010 22:24:16 GMT

...I saw my boss use euthapent to control status epilepticus in a dog, once. I still remember my reaction...good times. :p

(Basically, if you're using euthapent to control fits in a dog, it may be time to think about this dog's prognosis, folks...)

Re: Use by dates

Laurence Webb — Tue, 09 Nov 2010 21:44:19 GMT

[quote user="Bob Russell"]Are there any sterile preparations?[/quote]

I've just tended to use a new bottle of Euthatal/Dolethal etc and cross my fingers, which seems to work. I tend to worry more about the effects that yellow, blue or pink dyes have than the sterility.

Phenobarbital sodium 200mg/ml is shown on the BNF at £2.00 per 1ml amp if you want a sterile injectable barbiturate

Re: Use by dates

stephen sargent — Tue, 09 Nov 2010 18:56:13 GMT

Sagatal used to be 60mg/ml pentobarbitone, and euthatal is 200mg/ml, so I suppose you would use 1\3 dose rate as for sagatal.

Re: Use by dates

Bob Russell — Tue, 09 Nov 2010 17:57:17 GMT

What dose rate of pentobarb do you use for status epilepticus? Obviously it would be to effect but how much is it likely to take to render unconsciousness? Drops or mls? My patients at the end of the needle are not expected to wake up so I have always tended to be generous with it!

Are there any sterile preparations? Long acting barbiturates were always my drug of choice for status and metaldehyde poisoning but seem to be unavailable. Never thought of using Euthatal.

Re: Use by dates

Laurence Webb — Tue, 09 Nov 2010 16:32:03 GMT

Aren't the VMD more likely to clap you in chains of using pentobarbitone against it's license for treating status epilepticus? Surely you should be grinding Epiphen tablets into powder, mixing them in saline and injecting that?

Re: Use by dates

Martin Atkinson — Tue, 09 Nov 2010 15:14:27 GMT

Maybe its for the odd occasion when out of desperation because all other means have failed you want to use it to control status epilepticus with a sub-lethal dose. Of course they are so efficient that they would have taken this into consideration when determining the arbitary, whoops sorry - carefully considered use-by date.

Re: Use by dates

Michael Woodhouse — Tue, 09 Nov 2010 00:17:37 GMT

[quote user="Simon Neuhoff"]REALLY? You leave Pentoject in the car?[/quote]

Find me a large animal vet that doesn't?

Re: Use by dates

Edward Jones — Mon, 08 Nov 2010 15:48:12 GMT

[quote user="Anthony Todd"]But is it?[/quote]

All honesty - I don't know. I was only working on the basis of first principles - it just seems to me that efficacy and toxic metabolites issues are more to do with an appropriate use-by date stamped on to the bottle, rather than the 28 day rule. What the justification used by the VMD et al. is I don't know. I doubt they know.

[quote user="Simon Neuhoff"]REALLY? You leave Pentoject in the car?[/quote]

No! Sorry, I forget the emoticon!

Re: Use by dates

Simon Neuhoff — Mon, 08 Nov 2010 15:11:41 GMT

[quote user="i am ed"]

[quote user="Mark Holmes"]I have always found it potent enough![/quote]

I've never had a problem with the bottle of pentoject I keep on the parcel shelf in the car

[/quote]

REALLY? You leave Pentoject in the car?

Re: Use by dates

J G Wray — Mon, 08 Nov 2010 15:07:51 GMT

[quote user="Anthony Todd"]Showing that a particular bottle of a particular drug is uncontaminated at 29 days would not show that the drug is just as potent nor show that it had not decomposed into a toxic metabolite.[/quote]

That is true, but, I think you're getting ahead.

I'm also curious to see if vets, given enough self-interest, could organise to pay for and produce evidence rather than rhetoric.

JGW

PS As for potency, I'm pretty sure convenia is potent beyond the 28th day, if administered on the 28th day.

Re: Use by dates

J G Wray — Mon, 08 Nov 2010 14:57:23 GMT

[quote user="Bob Russell"]Not so much hot air as vets starting to fight back - even in a small way!![/quote]

Well, good luck, but your message looks to be founded on indignation rather than evidence. It also looks too ambitious to be realistic.

JGW

Re: Use by dates

Vikki Halliday LLB — Mon, 08 Nov 2010 14:47:55 GMT

Just before my new surgery opened, a member of the Pets at Home staff brought me her very poorly chinchilla to euthanase. I think the bottle I found in my "emergency" supplies in my car was last used in about 2001, to euthanase probably a calf, as the box bore the evidence of my previous life as a large animal vet!

It worked fine.

Re: Use by dates

Anthony Todd — Mon, 08 Nov 2010 13:57:37 GMT

[quote user="i am ed"]The 'thou shalt dispose of the remaining drug 28 days after the first dose was withdrawn' rule is primarily about contamination.[/quote]

But is it? The only justifications for the 28 day rule I have seen have been the laborious quoting of the rule, not the reason for it.

Re: Use by dates

Edward Jones — Mon, 08 Nov 2010 13:36:59 GMT

[quote user="Mark Holmes"]I have always found it potent enough![/quote]

I've never had a problem with the bottle of pentoject I keep on the parcel shelf in the car

Re: Use by dates

Mark Holmes — Mon, 08 Nov 2010 13:35:06 GMT

[quote user="i am ed"]

Anything in a brown glass bottle is usually unstable in light, so I imagine that a bottle of pentoject kept on a window sill could lose potency with time.

[/quote]

I have always found it potent enough!

Re: Use by dates

Hannah Wynne Richards — Mon, 08 Nov 2010 13:34:33 GMT

If the worry really is contamination-in other words,we can be trusted toscrub up properly for ops, but not touse a fresh needle for drug withdrawals ????????????????, why not have a really effective rule,and discard everything within 24 hours-or leave things as they were ???????????

Wynne

Re: Use by dates

Edward Jones — Mon, 08 Nov 2010 12:53:44 GMT

There's 2 slightly different issues here. The question whether the drug is potent and hasn't decomposed into a toxic metabolite largely governs the use-by date as stamped onto the bottle (usually a couple of years in the future).

The 'thou shalt dispose of the remaining drug 28 days after the first dose was withdrawn' rule is primarily about contamination. I suppose contamination could result in loss of potency/toxic metabolites, if the contamination (bacterial/fungal, say) digested the drug somehow, but it seems unlikely to me.

In the past I seemed to get more injection reactions from a bottle of long acting penicillin if it had been opened a while, although I suspect that would have been prevented with more careful spirit cleaning of the rubber bung. That was a long time ago - I'm a reformed character now!

Anything in a brown glass bottle is usually unstable in light, so I imagine that a bottle of pentoject kept on a window sill could lose potency with time.

Re: Use by dates

Anthony Todd — Mon, 08 Nov 2010 12:41:56 GMT

[quote user="Jonathan Wray"]HOwever, the use by date issue is much more straightforward to get evidence for to support a change in the marketing authorisation.[/quote]

It seems to me that we are being too simplistic.

Showing that a particular bottle of a particular drug is uncontaminated at 29 days would not show that the drug is just as potent nor show that it had not decomposed into a toxic metabolite.

It would be difficult to show that the drug was just as potent without the full cooperation of the manufacturer which I think is unlikely.

[ I would not be surprised if all the manufacturers already know the maximum shelf life of their preparations as they would have to be sure the preparation would pass the 28 day discard rule] Remember the original propofol only lasted a week didn't it?

I suggest a formal challenge to the VMD from the BVA ,via the cost penalties to the public , to provide any evidence that injectables degenerate after 28 days would be harder for the VMD and the industry to sidestep,

But would they mount the challenge??

Re: Use by dates

Bob Russell — Mon, 08 Nov 2010 11:37:33 GMT

[quote user="Jonathan Wray"]

I have watched the debate about the cascade system and the attempts to produce a body of opinion that could be used to lobby for a change in legislation. I think it is so much hot air, because there are too many vested interests in that little chestnut.

[/quote]

But at least we are doing something about it. The profession has sat on its backside and taken this rubbish with barely a murmur. I don't expect a major rethink because the pharmaceutical industry are running the way we prescribe.

Not so much hot air as vets starting to fight back - even in a small way!!

Re: Use by dates

Bob Russell — Mon, 08 Nov 2010 11:30:32 GMT

[quote user="Alan Tevendale"]

Jonathan that sounds like an interesting idea. Would it be worth getting a specific lab involved? I think I'd be up for the idea in principle. It might be a hell of an uphill struggle though.

[/quote]

I have already planned that come my VMD inspection one bottle will be outside this stupid disposal date and I will get it checked either by the manufacturer (unlikely to oblige!) or by my lab. If the results show that there is no contamination I would have a defence of sorts!!! One product, one practice - not exactly onerous. If a product is not efficacious on day 29 we will already know it in a lot of cases. Does that ketamine injection no longer work? Quite easy to find out!!!

Re: Use by dates

Alan Tevendale — Mon, 08 Nov 2010 07:55:57 GMT

Jonathan that sounds like an interesting idea. Would it be worth getting a specific lab involved? I think I'd be up for the idea in principle. It might be a hell of an uphill struggle though.

Re: Use by dates

J G Wray — Mon, 08 Nov 2010 07:32:33 GMT

[quote user="Anthony Todd"]A request for the scientific basis for the 28 day regulation was greeted with a prolonged explanation, quoting all the numbers, of the VMD regulation but nothing about the science or testing at greater periods.[/quote]

HOwever, the use by date issue is much more straightforward to get evidence for to support a change in the marketing authorisation.

A body of evidence could be acquired by asking veterinary practices to each choose some products they regularly use then donate the cost of a swab for culture and sensitivity from an open bottle 29 days after opening. Results could be collated and presented as evidence rather than hot air.

This would be the profession helping itself and the public. The VMD is not entirely immune to reason and persuasion, but is pretty deaf to rant and hubris.

Who would be prepared to put a modest sum where their mouth is?

I'd donate 10 swabs, either 10 products on day 29 or five at two different dates or whatever.

Then we could move on to efficacy studies.

JGW

Re: Use by dates

Anthony Todd — Sun, 07 Nov 2010 22:23:05 GMT

[quote user="Mark Holmes"]This does raise an interesting point, if the use by date on euthatal/ pentoject is based upon so little what is to suggest it is ever based upon more? They would appear to be arbitrarily imposed![/quote]

Yes, a direct copy and paste from the human EU regulations totally disregarding the fact that human injectables are single dose and open ampoules without preservative or fixed rubber caps.

Veterinary injectables are tested only at 28 days as that is the regulation's requirement so they could be fine for 28 years [as pentoject probably is]. And why would the drug companies demur?

I reckon most vets will discard more than they use in many cases and, of course, the public inevitably pays more, and the manufacturer inevitably makes more.....

A request for the scientific basis for the 28 day regulation was greeted with a prolonged explanation, quoting all the numbers, of the VMD regulation but nothing about the science or testing at greater periods.

Has there ever been a problem with an injectable proven to be caused by extended use [apart from vaccines, of course]?

Re: Use by dates

Mark Hedberg — Sun, 07 Nov 2010 21:20:35 GMT

[quote user="Laurence Webb"]

I'm shocked by the cavalier attitude towards use by dates shown on the forum. Using this after the 28 days has expired could be lethal.

[/quote]

I demand this man be awarded a medal of some type immediately. :)