Eli Lilly and Amylin Pharmaceuticals worked jointly to develop, test, and sell the type 2 diabetes drugs Byetta and Bydureon in the early 2000s. They are two different forms of the same generic medication, exenatide and were approved by the U.S. Food and Drug Administration (FDA) to help control high blood sugar levels along with the use of lifestyle changes like losing weight and eating a healthy diet.

For many patients, this newer type 2 diabetes drug has proven to be an important tool in combatting the illness. For others, though, the Byetta side effects have not been outweighed by any benefit. Instead these people have suffered more than they should have by experiencing complications like pancreatitis, kidney failure, and even thyroid or pancreatic cancer. As more evidence of the risks becomes clear, more lawsuits are being filed against the drug makers for producing such a potentially harmful drug.

Byetta and Bydureon

Byetta and Bydureon are both injectable forms of the generic drug exenatide. Byetta was developed first by Eli Lilly and Amylin and was approved by the FDA in 2005. It is designed to be used twice a day to help regulate blood sugar. A longer-lasting form of exenatide called Bydureon was approved in 2012. It only needs to be used once per week. Amylin Pharmaceuticals, along with the rights to the two drugs, was bought by Bristol-Myers Squibb in 2012.

Exenatide belongs to the class of type 2 diabetes drugs called incretin mimetics. They work by stimulating more production of insulin by the pancreas. Insulin naturally regulates blood sugar levels, but in someone with type 2 diabetes, less is produced or the body has become less sensitive to it. With more insulin produced thanks to exenatide, blood sugar levels go down. This is supposed to be used in conjunction with diet and exercise, lifestyle changes that can reverse high blood sugar.

Thyroid Cancer

Byetta and Bydureon may be effective in lowering blood sugar, but they also come with significant side effects for some patients. Most tolerate exenatide, but for those unfortunate patients who experience some of the rarer side effects, cancer may be the end result. One of the most recent discoveries about exenatide is that it can increase the risk of developing thyroid cancer. The cancer of this gland, which is important in regulating metabolism, is not common.

Much of the current evidence that exenatide may cause thyroid cancer comes from animal studies. Lab rats given the medication have developed thyroid cancer at abnormal rates. Any connection in humans has been harder to prove, but the evidence is compelling enough and the illness serious enough to require that Byetta and Bydureon carry warnings on their label information.

Anyone with a history of thyroid cancer, or even a family history of this type of cancer, is warned to carefully weigh the risks against the benefits of using exenatide. The FDA also warns that everyone taking the drug should watch for signs of thyroid cancer, which include a lump or growth in the neck, trouble swallowing, and hoarseness.

Pancreatitis and Pancreatic Cancer

Just as serious, but with stronger evidence of a connection, is the possibility that Byetta and Bydureon side effects may include pancreatitis and pancreatic cancer. Especially dangerous is the fact that the medications may trigger acute pancreatitis, the sudden onset of inflammation of the pancreas. It can be treated, but if it is not treated right away, it can be fatal.

Reports from individuals sickened in this way along with study evidence prove a definite link. Other incretin mimetic drugs have also been shown to cause this dangerous side effect. One study from 2013 found that the risk of being hospitalized for the acute condition was doubled in people taking any kind of incretin mimetic. Sometimes diabetic drugs are used in combination to increase the effect, but doing so with incretin mimetics further increases the risk of pancreatitis. Based on the evidence the FDA strengthened its warnings about pancreatitis in 2013.

There is even evidence that drugs like Byetta could increase the risk of patients ending up with pancreatic cancer, a severe and aggressive type of cancer. More research is needed, but one very interesting study investigated pancreatic tissues in deceased diabetic patients. Those that had used drugs like Byetta, incretin mimetics, had pre-cancerous cells in the pancreas. The FDA maintains the opinion that the evidence is not yet strong enough to make an official warning, but it looks like pancreatic cancer could be one more dangerous potential side effect of Byetta and Bydureon.

Other Byetta Side Effects

Cancer and pancreatitis are some of the most serious and potentially fatal consequences of Byetta and Bydureon, but there are also other more common and less serious side effects. The most common of these is nausea. It is reported most often, but patients also report that it tends to lessen over time and for most people totally disappear. In addition to nausea, many patients also experience dizziness, weakness, constipation or diarrhea, vomiting, headaches, stomach upset, and a jittery, unsettled feeling.

Skin reactions at the injection site of Byetta or Bydureon is possible, but not common. Some people will react badly to it and experience a rash. In worse cases the reaction may include blistering, swelling, infections and even open wounds. For some people the reaction can be severe enough to require surgery to treat the area. Also rare, but possible is an allergic reaction that can be fatal if not treated as an emergency.

Bristol-Myers Squibb and Eli Lilly are all responsible for Byetta and Bydureon and the side effects that they cause. Because some people have been so seriously harmed by exenatide, these companies have faced lawsuits. Plaintiffs in these cases claim that the drugs were sold and represented as safer than they really are and that the drug companies didn’t warn the public as it had a responsibility to do. If you were harmed by the side effects of Byetta and Bydureon, you may also want to file a lawsuit against these companies to seek much-needed compensation.