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RE: What's up with Crofab use?
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by bwanadon on September 18, 2011
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Thanks for your elucidation.
What has become clear to me from these discussions is that there is a great deal of conflicting evidence in the realm of snake envenomation and appropriate analysis/treatment; evidence that appears to come from equally trained and experienced professionals from all around the world including those kind enough to comment on this site.
To clear up one point, the earlier example given of the man bitten by C. adamanteus was, indeed, a serious bite and was treated successfully by 12 vials of CroFab. The man involved is extremely well known in the snake handling community and among the most knowledgeable. Apparently the neurotoxic effects of this bite actually rendered him unable to walk. His identity will remain unannounced here for his privacy. However, if you are intent on finding out who it was, you should read "Rattlesnake Adventures North South East and West".
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RE: What's up with Crofab use?
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by AquaHerp on September 18, 2011
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Yes indeed. There is a lot of conflicting data and ideas on the treatment of snakebite. What we once though was proper 20 years ago is not even considered safe nowadays. What we were sure of 5 years ago is now questionable at best. What we know today, will most likely be improved upon tomorrow. The issues surrounding this are plenty, because we are faced with so many variables. Each victim is different in age, health, sensitivity, attitude.... Each species is different in chemical composition, venomic strategies, volume delivery and so on. Then we see vast differences in venom profiles from the same species across geographic ranges as well as within siblings. Elapsed time post envenomation, placement of bite, physical stressors post bite and a long list of factors also add into this mix of what makes each bite unique. Perhaps one day....but until then we work within our means and understanding.
DH
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RE: What's up with Crofab use?
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by JoeCrotalid on September 18, 2011
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Yes, I would also like to see your data supporting your statements, and in addition, given your reluctence to fill in your profile have to question the validity of those statements. I apologize if my post was above your head, but this section is entitled "Ask the experts" and other than listing specific enzymes common in both Copperhead and Cottonmouth venom, I didn't feel that my post used big, medical sounding words. However, given that I am in the medical field and have been treating envenomations for over 20 years, I will attempt to address your most recent statements more on your level.
First, No one has made any statement suggesting that AV be used in all copperhead envenomations and certainly not prophylactically, but it has been shown in multiple clinical studies and individual case presentations to effectively limit local effects and resolve systemic effects of copperhead envenomation. You refer to 3 studies during clinical development and are incorrect...In fact, only 2 large clinical trials were performed during development, both which excluded copperhead envenomations due to its considered lower toxicity and the fact that many copperhead bites were not treated which would effect trial results. In addition, severe envenomations were excluded. However, multiple studies and case presentations have been completed since CroFab was released showing its effectiveness in treating copperhead bites. Here are just a couple:
1.) Chuang RC, Et Al. Rattlesnake versus Agkistrodon Envenomations: Venom Effect Differences. Involved 53 total Copperhead envenomations and included a dosage range of 2-22 vials for Agkistrodon envenomation vs. 4-32 for Crotalus/Sistrurus envenomations. All envenomations showed improved with AV.
2.) Scalzo A. Copperhead Envenomation: To CroFab or Not to CroFab. Of 596 cases reviewed, 87.7% were copperhead envenomations and all cases that received AV showed improvement, but that most copperhead bites are undertreated with AV.
3.) Whitlow KS. Systemic Effects After Copperhead Envenomation. Case study of severe envenomation by copperhead that developed coagulopathic effects due to envenomation. Effects resolved after an initial 6 vial bolus that did not acheive control and received additonal 4 vial bolus with resolution and completed 3 maintenance doses for a total of 16 vials.
All 3 of these papers were presented at Venom Week conferences which were certainly attended by medical professionals very familiar with treating envenomations, and...
4.) Lavonas EJ, ET AL. Initial Experience with CroFab AV in the Treatment of Copperhead Snakebite. Annals of Emergency Medicine. 32 Copperhead (Moderate)envenomations received CroFab with initial control of local effects except in 4 cases which required additional bolus doses due to continued progression. 1 of those cases was by an unconfirmed copperhead envenomation (patient stated it was a copperhead).
So yes, while not all copperhead bites require treatment with AV, studies do conclude benefit in treatment with AV including shorter "debilitation" time.
You also have an issue with dosing..."One size fits all" which doesn't make sense either since it has been pointed out that many physicians are unfamiliar with snakebites, and the standardized dosing of 4-6 vials provides the physician with a start point. Even the Wyeth polyvalent had a starting recommendation for copperhead bites of 5 vials, but was more of an administer AV...Reassess...give more AV...Reassess...etc. CroFab provides standardized dosing which is shall we say "Idiot Proof". This dosing regiment is also based off the clinical trials and patient response to dosing.
Next you criticize the manufacturer for simply in it to make money...we call that capitalism! Wyeth was in it to make money, Bioclon is in it to make money. Furthermore the reason CroFab is so expensive currently is because it remains under an active patent, but just as the Wyeth product, it's cost will drop when the patent ends. Which brings us to your next statement about AV and hospital administration costs.
To simply say that the cost of AV administration is excessive is an understatement. These cost far exceed just AV and its administration. These include the entire hospitalization, supportive care, IV fluids and medication, laboratory tests, nursing care, etc. If you think these costs are high, don't ever have a heart attack requiring cardiac cath or God forbid, Open Heart surgery. Plus take into account that many hospitals never resoup these costs because of uninsured patients being envenomated, so many are simply written off.
Plain and simple, AV is the mainstay of treatment as a general rule. You basing your statements off yours and yur families experience with envenomation. That doesn't equate to these individuals requiring the same care. Quite frankly I believe it is more negligent to allow someone to sit in a bed and continue to swell possibly causing more tissue damage and a period of extended debilitation vs. treat them with AV and possibly get them back in their saddle sooner.
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RE: What's up with Crofab use?
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by bwanadon on September 18, 2011
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At least most of us are not cutting and sucking anymore.
A personal observation. On my own bite a Sawyer kit was used within 5 minutes, perhaps less. The fang marks at 3/4" apart were too too far apart to cover both so the smallest single head was used on each fang mark separately.
Some of the pale yellowish venom was removed right away from one piercing. The other fang was into a slightly fleshier part of my foot and I was unable to see that any venom was removed from it. Nevertheless, by continuing suction on the first it began to bleed and suction was stopped. This fang mark developed a clot and later a large round scab the same size as the suction cup and this did not heal to clean new skin and the scab fall off for quite some time...well after becoming fully ambulatory.
I have no idea how much the suction helped though I believe it must have helped some. If used very quickly it probably has some value.
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RE: What's up with Crofab use?
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by bwanadon on September 18, 2011
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Profiles have nothing whatsoever to do with the discussion at hand. I enjoy my privacy.
I don't deny that treatment with CroFab can have benefits in treating Copperhead bites as your examples show. Nevertheless that doesn't address the bottom line as to cost verses benefit.
You mention CroFab has a standard "Idiot Proof" dosing regimen based on clinical trials but also say the clinical trials done by the manufacturer excluded Copperheads. That doesn't compute.
I didn't and don't criticize the manufacturer for wanting to make a profit. Nevertheless, profit is certainly a motive in wanting to sell a lot of something...no? I would certainly hope it is or capitalism would collapse.
Then too, if the costs of utilizing the patent are so high, could it be that the patent holder is putting profit ahead of human suffering. (Actually I don't think so but it could easily be one way of looking at profit from this patent.)
You go on to make one case for me - that hospital costs are staggering, which is a good reason to use such facilities carefully and even sparingly. Allowing someone to sit in bed may not be the more humane treatment when hitting them afterward with massive medical bills. My bite was very painful but didn't keep me from work more than 3 days, albeit hobbling around. Certainly it would have been different as a construction worker or the like. Getting them back in their saddle sooner might give them the ability to earn a wage for a few extra weeks but that will hardly make up for the cost of a stay in the hospital after which they may have to declare bankruptsy
I agree fully that the main cause of gargantuan hospital bills is the number of patients who pay nothing and not just for snakebite treatment. It gets added on to the bills of the rest of us!
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RE: What's up with Crofab use?
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by JHarrison on September 18, 2011
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I still don't see any reference for use of CroFab in S. America.....would really like to know your source for this.
Joe once again has said pretty much everything. Your confusion about copperhead vs. non-- look, dosage was determined from initial clinical trials. Then, during the course of life, people were bitten by copperheads and went to the hospital for treatment. Physicians were left with the decision to either treat them with CroFab, or give them no AV. Choices were made, presumably based on the opinion of the Dr. and on the case itself. Then, retrospective studies were done, and these showed that patients with copperhead bites did indeed improve with CroFab treatment. Its not that hard to follow.
If everyone had insurance, or if *GASP* we had socialized medicine, there would not be the problem of the uninsured passing on their costs to the rest of us. It sounds to me like you are suggesting that we withhold treatment based on whether or not we think said treatment is cost effective. Personally, I agree with you to some degree, and I would probably decline AV treatment for a copperhead bite unless I had some blood abnormalities. However, the way our system is set up there is no way for 'us' to make that judgement-- it is up to the Drs. to decide how to treat. Some people can take pain well- it sounds like you are one of them and you went back to work, etc. Good on you. However, there are lots of people who can not stand pain, and would be very upset if they discovered there was a treatment they were declined because it was deemed too expensive to use on them. Maybe that's not the ideal situation, but that's what we have now.
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RE: What's up with Crofab use?
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by JHarrison on September 18, 2011
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Forgot the most important bit: remember that paralysis, while certainly a symptom of neurotoxins, can also be caused by other things. For example, severe myotoxicity can cause paralysis, and it can even by psychological. From what I have read, only a very large bolus of EDB venom tends to result in neurotoxicity, and 12 vials would not have been enough to treat a very severe envenomation like that.
The only visible symptom (ie can see without running any tests) of neurotoxicity is ptosis. All others can be caused by other toxins as well as by neurotoxins.
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RE: What's up with Crofab use?
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by bwanadon on September 18, 2011
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I'm sorry about not being able to locate the use of CroFab in S.A. in the mountain of research - only that it did have some positive effect.
That CroFab has benefits in treating Copperhead bites has never been denied by me. What has prompted this discussion was whether or not it was necessary in most instances and there is conflicting opinion on that subject. There are lots of medical treatments which may have positive effect and yet are not necessary nor cost effective so cost should be one of the considerations.
I agree that choices are often made on the opinion of the attending doctor; however, final decisions on treatment should be made by patients - not doctors. Doctors should give advise on treatment and patients should make the decision. This is the very reason for "second opinions". So witholding treatment or not shouldn't enter into it. It isn't the dioctors decision to make. You tell the patient your best opinion on outcomes and the patient decides whether or not to get the treatment. The patient can also do the math on costs, given good medical advise. If an attending physician believes the patients decision endangers the doctor's livelihood that doctor should recuse himself/herself.
I'm also of the opinion that socialized medicine would pass the cost along to those of us who already pay the bills just as the present system does. No matter how it is structured, medical expenses have to be paid for or the system fails and the payors are always the same. There is no free lunch.
I also believe that socialism is the greatest governing system ever devised - until it runs out of other people's money.
Regarding snakebite pain - there are so many effective pain medications available it needn't be one of the reasons for administering AV...or not.
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RE: What's up with Crofab use?
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by AquaHerp on September 19, 2011
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Perhaps what you read was a reference of a study with CroFab against a South American species in a laboratory? There have been a few studies on the neutralization of some venoms with CroFab. I seem to recall seeing one recently on CroFab vs. Bitis gabonica venom.
In all cases that I am aware of, including my own, the attending physician only administers AV if absolutely needed. While CroFab is relatively safer than the equine based serums, it is still risky. Doctors are very reluctant to administer as "routine".
One should always keep in mind that AV will not reverse the damage done by an envenomation. It simply halts the process. If a doctor sees symptoms of this underway, then AV is certainly warranted. I've seen some nasty results from copperhead envenomations. I will always recall a conversation that I had with Sherman Minton years ago. He said that in all of the snakes he had interactions with and of all his accidents; it was a juvenile copperhead that gave him his worst bite.
DH
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RE: What's up with Crofab use?
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by bwanadon on September 20, 2011
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Agreed, serum treatments always carry some risk but still have doubts that most doctors are actually very reluctant to administer. Observation is probably the best first aid in snake bites.
It seems to me that swelling from a Copperhead bite, especially on the foot or leg is not, of itself, reason for an AV drip; while those on digits and face/neck are another matter altogether.
I believe the bite on my foot involved a pretty good dose of venom since that snake clearly had to feel very threatened (I was running right at and directly over it without realizing it was there.). A dimple from necrosis at the bite site might have been possible long term but that wasn't a particularly gruesome outcome to worry about even then.
That was an interesting aside about Minton's run in with a juvenile. I have a 1969 softcover copy of his book picked up for light reading in the Charleston, S.C. airport the same year. It's a fascinating read and my copy has become dog-eared and frayed.
I have learned some new information from these conversations and appreciate all the comments.
Here's to not getting bitten!
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