Since the 1920s, diabetics have had to go through the hassle of daily insulin injections. During that time, German researchers tried to discover more accessible and safer methods for diabetics to get their insulin needs and focused on an inhalable form of insulin. Their ideas eventually lead to the core concept of Exubera by Pfizer.
Pfizer Incorporated, based in New York (NYSE: PFE), is one of the largest pharmaceutical companies in the world. It produces the number-one selling drug Lipitor (Atorvastatin, used to lower blood cholesterol); the oral antifungal medication Diflucan (fluconazole), the long-acting antibiotic Zithromax (azithromycin), the well-known erectile dysfunction drug Viagra (sildenafil citrate), and the anti inflammatory Celebrex (Celecoxib) (also known as Celebra in some countries outside USA and Canada, mainly in South America).
Delivering Insulin by Inhalation Exubera is a type of inhalable insulin. It is administered through an inhaler, which sprays a form of human insulin into the lungs. Exubera works on similar principles as to how oxygen is absorbed. Oxygen flows into the lungs with a deep breath, makes contact with circulating blood, blood absorbs the oxygen, and is administered throughout the body. Exubera too is absorbed into the blood and regulates the amount of sugar within your blood. The inhaler is about the size of your hand when it is compacted, and about one foot long when it is being used. Some folks refer to it as a "bong".
The drug Exubera is a powdered insulin that is sprayed into the lungs. This insulin is derived in the lab by using recombinant DNA technology. This method involves the use of laboratory 'factory cells'. Scientists expose these cells to specific chemical signals that result in the mass production of insulin. Scientists produce in the insulin in this way because it is difficult to synthesize consistently and in high quantities. The insulin they recover from these cells is the basis for what is sprayed into your lungs. This is a very innovative method for producing biological substances in mass quantities.
Exubera works by going into the blood and regulating glucose levels. In a normal pancreas, insulin is produced when blood sugar levels get too high in the blood. In other words, insulin is used to regulate high levels of blood sugar and low levels of blood sugar. Those who would benefit from Exubera are those with type 1 diabetes because of their daily need for insulin. Exubera is different from other forms of insulin intake because it is taken through an inhaler instead of an injection. Human insulin, derived from recombinant DNA technology, is put inside an inhaler. Then, a blister surrounds the insulin, acting like a medicine capsule to safely deliver the insulin into the body. Some of the insulin is absorbed and degraded inside the lung and some of it is absorbed into the blood.
Exubera's Safety Concerns
Exubera may sound like the end to needles for Type 1 diabetes patients who have to administer insulin intravenously. However, there are many issues and ongoing concerns with this drug. The first and foremost concern with the drug is the controversial approval by the FDA. Exubera is the first protein sprayed into the lungs that has been approved by the FDA. There has been much criticism of the FDA since 2004, and Exubera only adds to the list. Approval by the FDA was questioned by critics because of inconclusive clinical trials. For example, the effect of Exubera on those who have been smoking for the past 6 months is very serious. Lungs of smokers have the tendency to absorb more insulin, thereby decreasing blood sugar at a higher rate. Therefore, smokers run a higher risk of hypoglycemia. Absorption rates are increased anywhere from 2 to 5 times higher of non-smokers.
Many users, after the FDA had already given their approval, have reported trouble breathing after inhalation. There has been recent scientific discussion on decreasing lung capacity and damaging lung tissue. Although the FDA has approved of Exubera, there are still clinical trials testing for the long term effects on lung tissue. Exubera has been known to be especially dangerous with those with underlying lung disease. It is difficult to characterize those with stable or unstable lung disease. Because Exubera is so heavily dependent on healthy lung function, and the difficulty to characterize the stability of one's lungs, Exubera runs the risk of overdosing many patients.
The National Institute of Health in the United Kingdom did not approve of Exubera. Their opinion on the matter was that Exubera "should not be recommended because it could not be proven to be more clinically or cost effective than existing treatments." Their reaction reflected that the use of Exubera did not better control blood sugar more accurately or consistently or at a more competitive price. In fact, the National Institute for Health and Clinical Excellence Exubera estimated Exubera to be about $60 a year more than insulin injections. The Institute for Safe Medication Practices has also shown concern about its prescription to users. The dosage of Exubera is not consistent with the units of traditional insulin injections. For example, Exubera is usually described in mg (milligrams) while insulin is described in units. This leaves room for error. Also, there is a non-linear relationship between mg and units of insulin. For example, 1mg is equivalent to 3 units of injected insulin. However, 3mg is not equivalent to 9 units of injected insulin. This non-corresponding relationship only increases the danger of dosage. This is a real danger because Exubera is oftentimes prescribed in addition to insulin injections.
FDA Fast Stamp of Approval
Critics believe the accuracy is nowhere close to the FDA's normal standards. The implications caused by lung disease, especially ones that are undetectable, create a risk for all users. This inaccuracy could have serious health risks. The only positive aspect of Exubera is that it is needle-free and may be less of a hassle during social situations. However, I do not think this is much of a positive aspect because if one were to use this inhaler in public, one should do it in a safe area such as a restroom. There are not many more locations you can use Exubera in that you can't also administer insulin intravenously. Also, the fact that it is more expensive puts Exubera in a worse position than before. Using Exubera requires routine trips to the doctor to ensure healthy lung function. These trips are not always covered by insurance companies, resulting in hidden fees and higher cost to the user. HMOs will likely not approve the costs of the Exubera treatments which are double the cost of insulin injections. Side effects for drugs are always an issue. The FDA generally decides if the health benefits outweigh the cost of side effects. Administering insulin with an injection has little side effects if the user is trained. Exubera, at the cost of compromising lung capacity and lung tissue damage, merely eliminates the user error.
At this point, it is remarkable how Exubera has been approved by the FDA. Upon closer inspection, there have been some controversial techniques of marketing the drug to the public. Dr. Edward Ryan, a Canadian Endocrinologist, commented on the convenience and efficiency of the drug, claiming that Exubera is "obviously an advantage...I would say the majority like it." Although this may appear wholesome, the Canadian Diabetes Association has found his research to be funded by Pfizer, the manufacturer and producer of Exubera.
The FDA has been under heavy criticism in the past few years. After knowingly allowing the drug Vioxx to stay in the market for four years, despite its proof of serious side effects, the FDA has come under careful scrutiny. The approval of Exubera has lead to ever closer investigations. Of the nine voting board members, three have been found to have consulted with or spoken with Pfizer. Which is more surprising is that the panel chairman has stock with Pfizer as well.
Should you use Exubera?
If you are considering Exubera, the best decision you can make is an informed one and of course talk to your doctor. Be aware that the side effects are much more serious than other FDA approved drugs and may be a large price to pay just to avoid insulin injections. Exubera is an alternate delivery method of insulin, nothing more. Remember, the FDA approval is not an indication of safety. It is an indication of research; be sure to know all of its effects on your body. Pfizer has pulled Exubera from the market, there are other similar products in the pipeline from competitors. Although inhalable insulin has been associated convenience with some diabetics, it should also be associated with consumer caution.
Mr. Sudeep Misra is a research associate for http://www.BlueSparrowMedical.com - Innovations in Diabetic Care. He is a senior undergraduate student in the bio-medical program at the University of California, Irvine. His research interests are in endocrinology and nephrology.
