- AACE PATIENT SAFETY EXCHANGE -

AACE Patient Safety - Editorials

Editorial on Byetta (exenatide) and Patient Safety

2008-08-25 16:22:21
By: Richard Hellman, MD, FACP, FACE

The recent FDA alert regarding Byetta¹ (exenatide) should be noted with concern. The mortality rates of severe acute pancreatitis in published reports is variable, but is usually reported to be over 10%. In the six cases the FDA reported of acute hemorrhagic pancreatitis, the mortality rate was 33%. In the previous FDA report on exenatide in 2007, none of the cases of pancreatitis led to death, although there were serious complications in several cases.

What we do not know – as is so frequently the case – is what the true incidence is of pancreatitis in patients who are placed on exenatide. Is pancreatitis on exenatide a rare phenomenon, or is it far more common than presently reported? We simply do not know the answer. There are many patients who are currently doing very well on exenatide, probably hundreds of thousands of patients at last count. However, exenatide often is not tolerated because of nausea and vomiting. We do not have data from post-marketing studies as to how often those symptoms, which may have preceded the cessation of the drug, were associated with a very mild episode of pancreatitis.

The New England Journal of Medicine's series of letters, "Exenatide and Rare Adverse Events"², published May 1, 2008, is also relevant, since Dr. Pablo Cure, one of the authors, reported on a patient on exenatide who developed a gastric bezoar, a very serious cause of nausea and vomiting, another complication that would also necessitate cessation of exenatide. Although the NEJM response from Amylin, the manufacturer of exenatide, indicated that they knew of only one other case, I have another. A 51-year-old woman with type 2 diabetes of 12 years duration, without significant peripheral neuropathy and no prior history of gastroparesis, developed intolerance to exenatide after starting the medication in July 2005. She stopped the medication three months later, and two months after that an endoscopy revealed a gastric bezoar. I, as many of my colleagues, realized that the clinical information was important but did not take the time to report the case either as a case study in the literature or as a report to the FDA.

It is hazardous for anyone to extrapolate from the one case I report and estimate the incidence of gastric bezoars or severe gastroparesis that have developed as a result of exenatide therapy, but we clearly need more data. We also need more physicians to ask the question as to why their patient is not tolerating exenatide, obtain relevant data at the time of the symptomatology, and share the data that may indicate more serious complications such as pancreatitis and gastric bezoars, either by reporting the data to the FDA, or in the literature, or both. We need to know the frequency or rarity of these serious complications. We also need data regarding the comorbid conditions and demographic data on the patients who are having the more severe problems. It may be that exenatide is safe for nearly all patients but not for some patients because of their risk factors for complications, risk factors that may still be unknown.

I hope that the Sentinel system of drug reporting will increase the responses to the FDA, but we also have a responsibility, both as individuals and as a professional society, to share what have learned. The tools we use for our patients are often highly potent therapeutic agents, all of which have potential limitations on their optimal and safe use. Exenatide, a truly remarkable medication, whose mechanism of action is complex and yet incompletely understood, will need closer scrutiny and more complete post-marketing data. Once again, in hindsight, it is clear that a more extensive, detailed and expensive outcome study would have been most helpful.

It is likely that some hard negotiation between the pharmaceutical industry and our government will be needed, so we can do a better job protecting the safety of our patients without stifling drug development. Perhaps a private/public partnership to pay for the needed studies is the answer. Perhaps changes in the length of patents may be another solution, but it is clear that our present system of drug approval sometimes not only puts our patients at risk, but also results in events that unfairly label drugs that are useful as "bad", when the fact is that they are good drugs for many, but not all. A more robust front-end evaluation of drug safety may be in the interest of all.

References:

FDA Alert on Byetta - http://www.fda.gov/cder/drug/infopage/exenatide/default.htm
"Exenatide and Rare Adverse Events", correspondence in New England Journal of Medicine 2008;358:18:1969-1972

Leave a Comment

There are 7 comments

Prasanna Rao-Balakrishna – UK

July 14, 2009 - 17:23

Subject: Preventing Hypoglycaemia is as important as the tight glycaemic control

Preventing hypoglycaemia is as important as the tight glycaemic control. It is important to note that glycaemic control depends on the insulin regimen, patient's own counter regulatory hormone response & insulin resistance status, the calorie intake, frequency of testing for blood glucose, interpretation and acting on the results. During acute illness it is not possible to control the counter-regulatory hormone response and the insulin resistance status, but with adequate training, frequent testing and appropriate structured response should be possible, thereby preventing a hypoglycaemia. A trial which focuses as much on hypoglycaemia avoidance as well as tight glycaemic control is needed.

Reply to Prasanna Rao-Balakrishna

Richard Hellman MD

July 16, 2009 - 11:25

Subject: RE: Preventing Hypoglycaemia is as important as the tight glycaemic control

Dr Rao-Balakrishna makes a very interesting suggestion, that preventing hypoglycemia is as important as the tight glycemic control, and suggests a trial that focuses on two end-points, the avoidance of hypoglycemia as a co-equal goal in importance to tight glycemic control.

In fact, there is a great deal we do not know about hypoglycemia in critically ill states, and it is far from clear what the short and long term consequences are of mild, moderate, or even brief periods of severe ypoglycemia for critically ill patients. We do know that severe hypoglycemia can be a marker for increased mortality, as it was clearly shown in the VADT trial, but interestingly, those deaths did not usually occur during the hypoglycemic episodes, and the relationship between severe hypoglycemia and subsequent mortality was strongest in the conventional therapy group, suggesting that the hypoglycemic events may have been a consequence of an underlying vulnerability rather than the cause of mortality.

One of the limitations of an approach focused just on the outcomes of glycemia is that from the patients' standpoint, the most important issues are their clinical outcomes: mortality, morbidity, and disability. In contrast, those outcomes may not match the relative frequency of hypoglycemia at all. For example, there is a disconnect between the very high frequency of hypoglycemia in the Van Den Berghe RCT's in critical care published in 2001, 2006, and 2009. Both the surgical ICU study of 2001 and the 2009 pediatric studies showed very excellent outcomes with respect to mortaliy and morbidity in the presence of relatively frequent hypoglycemia.

I again would like to thank Dr Rao-Blakrishna for pointing us again to this very unsettled issue of the importance of hypoglycemia prevention, for the debate as to what we can and should do rages on. There are many creative ideas that have been proposed, but we need more data to guide us as to how to obtain the best clinical outcomes with the tools we have without either unacceptably high levels of hypoglycemia or hyperglycemia.

Richard Hellman MD
Editor-In-Chief
Patient Safety Exchange Website

MRR – Texas

March 31, 2009 - 16:29

Subject: NICE_SUGAR

Several interesting points came to mind when I reviewed the NICE-SUGAR study; the degree of severe hypoglycemia, the degree of cardiovascular mortality, the conventional group’s blood glucose levels are significantly lower than the vast majority of other outcome studies, and the number of severe septic patients in the intensive control branch of the study. According to the 2008 sepsis guidelines, the glycemic control target level for the septic patient is already in question and perhaps sepsis should be an exclusion criteria?

I was tasked with the development and oversight of a Tight Glycemic Control Program pilot study from May 2006 through April 2008 for a South Texas community hospital/level 2 trauma center. This included a 14 bed CCU, 12 bed M/S ICU and 12 bed trauma ICU as well as 4 M/S wards. Clinical inertia was our most difficult element to overcome and for the most part this was never accomplished. Clinical inertia was not only evident on physician's part, but also administration, nursing, nutritional services, pharmacy, and the patients themselves. Accountability to noncompliance to protocols was lacking as well. The philosophy that inpatient glycemic control was not necessarily treating diabetes, yet acute hyperglycemia was never fully accepted. When results like ACCORD, ADVANCE, and VADT were released, I would usually take the phone off the hook and leave the hospital because those wbeepdo not support inpatient glycemic control would come out en mass wishing to compare apples to oranges. That is not necessarily the case with NICE-SUGAR. In our Trauma ICU, where support was highest, for the entire year of 2007, we had only 7% BG > 200mg/dL, less than 2% hypoglycemia under 50 mg/dL, and nearly 75% BG between 80 - 150 mg/dL.

Overall, I applaud the NICE-SUGAR research team for a job very well done and thank them for their contribution to this ongoing discussion. I do support further research to differentiate specific glycemic control target ranges for specific diagnosis, but I too fear this could cause a pendulum swing in the opposite direction resulting in less facilities participating in inpatient glycemic control resulting in less data for differentiation.

NISSIM GABAY – VENEZUELA

March 26, 2009 - 15:25

Subject: NICE -SUGAR

I think that the central goal of the ADA/AACE impatient glucose targets is safe with the protocols .
Hospitals should have protocols in place for using insulin to treat and prevent hyperglycemia.
Subcutaneous insulin may be used for both purposes in most noncritically ill patients, whereas intravenous infusion of
insulin is preferred in critically ill patients.
Be careful with this trial [NICE -SUGAR] to overcome clinical inertia.

Dr. Orlin Sergev – Charleston, SC

March 16, 2009 - 16:28

Subject:

Dear Dr Hellman:
I enjoyed all the editorials on patients' safety that you have recently published. I think that they raise questions which we as physicians are not always open about. Safety itself is frequently a topic that we love to discuss but it's never our fault. In this connection, the article about overconfidence and medical errors is timely - especially, at this time of expected health care changes. Briefly, I do not think we as physicians are different from any other specialists in different areas. Lack of adequate knowledge in a special area is always a good reason to be noisy and seemingly overconfident. Most of us agree that the more you know the more you realize how much more you do not know. Overconfident behavior in front of outsiders seem to be the cover of ignorance. I think we have to improve medical education in order to make medical decisions safer. Just remember the pilot of the plane that landed in Hudson river - quiet professional on top of his performance. We in medical profession must lead in patients' safety. In order to do that we have to lead the health care reform. We have to regain our authority, responsibility and accountability. (accountability without authority and responsibility is meaningless - see Dr Hellman's article on Medicare). We have to lead the health education of the society - most of the tragic mistakes in life happen from ignorance. First and foremost, of course, we have to maintain the superiority in medical knowledge. We must improve the quality of medical education. Instead of multiple choice questions we have to put back in place the stern professor wbeepmade clinical judgements based on knowledge, experience, and gut feeling and set up a good personal example for the next generation of physicians. Pilot "Sully" did not read the manual and the guidelines how to handle the critical situation - all his life before, however, prepared him for the right on the spot decision. Decisions based on profound knowledge and experience are the safest! Let's start the health care reform with ourselves.
Do not stop learning and teaching your team about sound and safe medical practices. When we have achieved that, we can confidently go out and regain our authority over various bureaucracies (government agencies-Medicare, insurances, medical malpractice law, etc).

james t poulos – west lafayette in

March 03, 2009 - 15:09

Subject: NICE-SUGAR

There was an article in acta scandinavia in january that showed very little hypoglycemia when intensive therapy is done right! I came across the article on medlinx in mid January, but it was actually published in October 2008. authors: Kaukonen KM et al in acta anaethesiol scandinavia and titled severe hypoglycemia in intensive insulin therapy.

Reply to james t poulos

Dr Hellman

March 04, 2009 - 16:12

Subject: Further thoughts related to the NICE-SUGAR study

Dear Dr. Poulos,

Thank you for calling attention to the study by Kaukonen KM et al. Your excellent point adds to the discussion generated by the NICE-SUGAR study. Their preliminary data analysis showed that error by provider was the most common cause of hypoglycemia. Their data implied, as I stated in my recent editorial, that improving the training and performance of those managing the insulin infusions greatly decreases the threat of hypoglycemia.

In this study by Kaukonen, done at the Helsinki University Central Hospital in Helsinki, Finland, the authors evaluated the incidence of hypoglycemia in all patients treated in two intensive care units between February 2005 and June 2006. They showed that severe hypoglycemia during intensive insulin therapy was rare in clinical practice. Analyzing data for 1124 patients and 61,203 glucose measurements, they found 36 measurements of severe (≤ 2.2mmol/L) hypoglycemia in 25 patients, with an incidence of 0.06% of severe hypoglycemia.

They commented that the frequency of blood glucose monitoring correlated inversely with the frequency and magnitude of severe hypoglycemia. In surgical patients, it is of note that five of the six instances of hypoglycemia occurred when a nurse failed to comply with the protocol.

The Helsinki group’s observations are entirely in keeping with the preliminary data from the NICE-SUGAR study and make a good deal of common sense. When the rate of decrease of glucose is rapid, for example greater than 1mg/dl/minute, simple arithmetic can tell us when the next glucose determination needs to occur to be able to safely avoid severe hypoglycemia. But if the frequency of checking of glycemic levels is arbitrary, and set too low, then hypoglycemia is to be expected much more often. The Kaukonen group avoided this by making sure the blood glucose sampling was relatively frequent.

In our clinical practice setting as well, the principles of safe handling of insulin infusions have been:

1.frequent monitoring, always at least hourly in ICU settings, more often when dealing with lower glycemic levels;
2.intensive training of nurses to make them expert in understanding how best to use algorithms;
3.specific points at which prolonged hyperglycemia or hypoglycemia necessitates immediate consultation with the responsible physician;
4.review of data to indicate variations in performance and appropriate correction and retraining when appropriate.

We too have extensive experience over many years with the safe use of insulin infusions in inpatient settings with relatively rare severe hypoglycemic episodes and little morbidity.

The NICE-SUGAR study should provide important information. We should not get too far ahead of their forthcoming data, but there is already abundant data, such as the important study from Helsinki, which show us that with a safer system of care, more ambitious glycemic control is both achievable and safe.

Kaukonen KM et al. Severe hypoglycemia during intensive insulin therapy, Acta Anaesthesiol Scand. 2009 Jan;53(1):61-65. Epub 2008 Oct 20.