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Herman Rubin <hrubin@xxxxxxxxxxxxxxxxxxxx> wrote on 13 Sep 2005 14:07:25
-0500:
> In article <5d86gd.76.ln@xxxxxxx>, Alan Mackenzie <acm@xxxxxx> wrote:
>>Sbharris[atsign]ix.netcom.com <sbharris@xxxxxxxxxxxxx> wrote on 11 Sep
>>2005 16:14:52 -0700:
>>>> Colleen Fuller:
>>> But the review's suggestion that it was somehow mere "marketting
>>> strategies"[!] that "suggested that the lower immunogenicity of human
>>> insulin and the anticipated decline in antibody titres would offer a
>>> clinical advantage for insulin-treated patients," is nonsense!
>>I read that review once. Nowhere do I remember them mentioning
>>market[t]ing stragies. As for "suggesting" them - Any such suggestion
>>would have been in the minds of the readers.
> The suggestion has strong biological reasoning behind it.
Er, I meant the suggestion of "market[t]ing strageties" was absent from
the Cochrane review. Sorry for the ambiguity.
> The insulin produced by the insertion of human insulin genes in
> microorganisms is identical with that made by the persons whose genes
> were do introduced. It is far easier to remove the possible
> contaminants. From what I have seen, humans produce the same insulin
> molecule, which is slightly different from that produce by animals
> which are normally processed in slaughterhouses.
>>> At the time, no endocrinologist (involved in marketing or not) guessed
>>> otherwise (if you want to argue that, find me the cite). Nor did the
>>> Cochrane Review suggest (before the fact) that it might not be the
>>> case. This result took EVERYBODY by surprise: industry, academia,
>>> practising physicians and patients, alike.
>>This is the sort of reason why most drugs have to undergo proper testing
>>before being introduced. Why genetically engineered insulin was allowed
>>to be an exception is the real mystery.
> Humulin and Novolin are not "genetically engineered" molecules.
Hello, purely semantic discussions! They are made using genetic
engineering techniques. They weren't properly tested before being
unleashed upon us.
> They are, apart from the few impurities and the additives deliberately
> put in for preservatives and stabilizers.
They are what? I don't think you finished the sentence there.
> Humalog and Novalog are genetically engineered, and I believe had to go
> through a testing processes, and are still available by prescription
> only. The same is true for Lantus.
They went through a nominal, rushed testing process for form's sake - one
which didn't pick up on the loss of hypo symptoms or "dead in bed
syndrome". I thought Lantus had been through a proper testing process.
> ....................
>>I was there too. And my insulin was casually switched over to GE
>>insulin by my doctor (A GP, not a diabetes specialist of any sort).
>>The new stuff wasn't as good as the old. Unlike the drugs you are
>>referring to, the were no pressing reasons to stop using natural
>>insulin.
>>>> "Human" insulin is not less likely to produce antibodies than pork
>>>> insulin. We know why those who use pork or beef insulin produce
>>>> antibodies, but it's not clear to me why antibodies result from the
>>>> use of an insulin whose molecular structure is identical to the
>>>> human insulin molecule. Some (Lewontin, eg.) have suggested that the
>>>> folding and unfolding action that is used to produce the human
>>>> insulin molecule is responsible for some of allergies and other
>>>> problems associated with the resulting insulin.
>>Quite likely, the "human" insulin molecule is not identical to the
>>human insulin molicule at all; .
> If it was not identical to the human insulin molecule, this would be
> known. Biochemistry can tell us exactly where in the amino acid chain
> beef and pork insulin differ from human insulin. They could tell
> whether the insulin in Humulin or Novolin is different from the insulin
> found in the blood of healthy people.
I think the suggestion is that although "human" insulin has the same
amino acid sequence as human insulin, it is "folded" differently, in some
fashion, has a different shape, hence is being recognised by the body as
foreign. It's not a topic I'm well up on.
[ .... ]
>>> COMMENT:
>>> Ahem. "Safe" you say?
>>It [beef insulin] is safe in the sense that it is known (from around 80
>>years of use) to have no long term side effects. It does not cause
>>cancer, for example. The same is not yet known for recently introduced
>>drugs such as Lantus. Beef insulin is also robust (it's not sensitive
>>to hot weather), and easy to use (for example, it can be mixed in a
>>syringe with other insulin). Put it in a fridge, and it will last the
>>best part of a century.
> You mean the same is not true of human insulin?
The same is true of human insulin, to within a tiny epsilon of certainty.
But not, as yet, of any analog.
[ .... ]
>>Which raises the much bigger philosophical question, should we
>>diabetics be expected to have to chose from amongst whatever drugs
>>Novo, Lilly and Aventis find profitable to make? That is pretty much
>>the way things are at the moment. The other extreme would be for
>>regulatory bodies to specify rigidly what products are to be made.
>>Doesn't seem much better. The real problem is, the supply of insulin
>>is a monopoly, not a free market. If I had my way, there _would_ be a
>>free market, one in which the existing monopolistic powers would be
>>severely curtailed.
> No, the supply of animal insulin IS a free market. Even the supply of
> most vaccines is essentially a free market. Try to find enough
> manufacturers; nobody seems willing to enter the market without
> government safeguards agains legitimate or illegitimate suits.
The supply of animal insulin is NOT a free market. An essential
attribute of a free market is that customers can pick and choose amongst
an abundance of suppliers. This was the case for insulin 40 years ago.
It isn't now. Another essential is that no supplier (or small band of
them) is powerful enough to dictate what customers will buy. In these
senses, computers are sold in a free market - You can buy one made by HP,
Dell, Apple, ..., or one assembled by your local corner shop. And if any
of these (apart from Apple, perhaps) decide to stop making computers, you
can get one just as good from somebody else.
The natural insulin "market" is not like this at all. (Nor the analog
"market" either, for that matter.) Diabetics using these products are
pretty much dependent on a single supplier. When Berlin Chemie stopped
making pork insulin earlier this year, it's users were told bluntly (by
the German health funds) "Tough! You'll just have to use GE instead".
And in the USA, people like Willbill and BNF have to jump through
incredible hoops to get natural insulin imported.
And as for "human" insulin? Well, Novo is beginning to turn the screws
on that, too - it doesn't make as much profit for them as analogs do. In
the UK, they have announced they are going to stop supplying pen
cartridges with GE insulin. This will no doubt "persuade" many diabetics
who value the convenience of the pen device to convert to analogs. No
doubt, in five or ten years, Novo will be able to say that there's "no
market" for human insulin any more, and withdraw it completely, forcing
users of "human" insulin to convert to analogs. In a truly free market,
such chicanery would not be possible.
[ .... ]
>>Been there, done that, got quite a few teeshirts. I tried Humalog
>>once, as a correcting drug, not (thankfully) my main insulin. The
>>stuff died after two days of at least two summer holidays. It died
>>within a few weeks of my carrying it back and forth with my normal
>>insulin. ~80% of the total I was ever prescribed ended up being
>>chucked out.
> Did you keep it cold enough? It is more fragile than Humalin, as it is
> a different molecule. I have used one vial for more than three months
> without it losing effectiveness, but I keep it refrigerated, or using
> an ice-pack carrier, for that period. There were some hot periods for
> one of the vials, and I was worried about the effectiveness of the ice
> packs.
Of course I didn't keep it cold enough. How could I possibly know it
needed special treatment? There was nothing in the packaging to suggest
it needing any gentler handling than insulin. Only the standard "< 30°,
for up to a month" which has been appearing spuriously on insulin
packaging for over 40 years.
>>When I needed an insulin change a few years back, my last doctor told
>>me "convert to Lantus, go onto the pump, or stay with GE NPH[*]. I
>>refuse to even consider animal insulin.". I found a more suitable
>>doctor.
>>[*] For those not in the diabetic groups, NPH is a delayed action
>>insulin, delayed by protamine extracted from fish testicles, and is
>>notorious for causing symptom-less hypos (low blood sugar), and having
>>an enormous action peak around 4-6 hours after injection. YUCK!!
> I have a problem with a peak around 10-12 hours after NPH. But I do
> not find the hypos any more symptomless.
Any more than what? Do you mean you used to find them symptomless, but
not any more? Or are you comparing NPH hypos with those caused by other
insulins or analogs?
I wasn't meaning to suggest that that experience with "human" NPH was
universal; only that it was very common. So common, in fact, that
"human" NPH makes an ideal standard of comparison for makers of new
analogs to test against.
> .......................
--
Alan Mackenzie (Munich, Germany)
Email: aacm@xxxxxxxx; to decode, wherever there is a repeated letter
(like "aa"), remove half of them (leaving, say, "a").
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