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Januvia & Byetta Side Effects

Januvia (sitagliptin) and Byetta (exenatide) are drugs used in the treatment of diabetes mellitus type 2. Januvia works by inhibiting an enzyme that breaks down insulin-producing hormones, allowing for more insulin to be released in response to a meal.  Byetta works by mimicking the effects of these insulin-producing hormones. The resulting natural release of insulin promotes proper digestion of sugars and a normal blood sugar level. However, some serious Byetta and Januvia side effects have been reported and patients should consult with their doctors to weigh the risks of these medications against their benefits.

Januvia Side Effects Exam by doctorJanuvia and Byetta FDA warnings

Januvia was first approved by the FDA in October 2006, after clinical trials lasting from 12 weeks to over a year in length. The FDA approved the medication, part of a new class of drugs called DPP-4 inhibitors, as a supplement to diet and exercise measures taken to control blood sugar levels in patients with type 2 diabetes. The most common Januvia side effects reported in trials were upper respiratory tract infection, sore throat, and diarrhea.  Byetta was approved in April 2005, after 30-month clinical trials revealed that the most common side effects were nausea, vomiting, and dyspepsia.

Since their initial approval, the Januvia and Byetta prescription information labels have undergone several changes, and now include warnings about potentially serious side effects and dangerous conditions caused by the drugs. These warnings involve pancreatitis, renal impairment, hypoglycemia, hypersensitivity reactions, and macrovascular outcomes.  In addition to these warnings, Byetta side effects may also include an increased risk for gastrointestinal illness and a possible immune response to the medication.

Summary of Januvia and Byetta label warnings and precautions:

  • Pancreatitis – Januvia and Byetta may cause potentially fatal cases of pancreatitis
  • Renal Impairment – Januvia and Byetta may impair kidney function or cause acute kidney failure
  • Hypoglycemia – Januvia and Byetta may lower blood sugar by increasing the hypoglycemic effects of other diabetes drugs
  • Hypersensitivity Reactions – Januvia and Byetta may cause serious allergic reactions in some patients
  • Macrovascular Outcomes – There is no evidence that Januvia or Byetta reduces the risk of vascular disease associated with diabetes
  • Gastrointestinal Illness – Byetta is not recommended for patients with gastrointestinal disease
  • Immunogenicity – Byetta may create an immune response that decreases the drug’s effectiveness

The FDA label also warns about adverse reactions which have been reported by doctors who prescribe Januvia or Byetta.

Byetta and Januvia side effects reported by medical professionals include:

  • elevated liver enzymes
  • acute pancreatitis
  • hemorrhagic pancreatitis
  • necrotizing pancreatitis
  • worsening kidney function
  • acute kidney failure (sometimes requiring dialysis)
  • constipation
  • vomiting
  • nausea
  • loss of appetite
  • headache
  • joint pain
  • muscle pain
  • limb pain
  • back pain
  • somnolence
  • dysgeusia (distorted sense of taste)

Byetta, Januvia and Pancreatitis

The pancreas is an organ near the stomach that secretes enzymes and hormones used in digestion and other vital bodily functions. Pancreatitis is the inflammation of the pancreas, which is a medical emergency and demands immediate treatment to prevent severe organ damage and fatality.

The FDA is currently investigating the link between Byetta and Januvia and pancreatitis, based on medical examinations and post-market studies that suggest that these medications can significantly increase the risk of pancreatitis. The FDA points to a report that Januvia doubles a patient’s risk of pancreatitis, but a 2011 study in the journal Gastroenterology found that Byetta, Januvia, and related drugs carry six times as much risk of causing pancreatitis as other diabetes treatments. The FDA has also instructed Merck Sharp and Dohme Corp., makers of Januvia, to perform additional laboratory tests on rodents to establish the exact level of pancreatic risk posed by Januvia, and has reprimanded Merck for failing to comply with this request in a timely fashion.

Pancreatitis caused by Byetta or Januvia can be life-threatening and the FDA recommends that these medications be discontinued if pancreatitis is suspected. The agency has received reports of both non-fatal and fatal pancreatitis in connection with these drugs, including hemorrhagic or necrotizing pancreatitis.

The following are symptoms of acute pancreatitis:

  • Swollen and tender abdomen
  • Fever
  • Increased heart rate
  • Upper abdominal pain
  • Abdominal pain that radiates to your back
  • Abdominal pain that feels worse after eating
  • Anorexia
  • Nausea
  • Vomiting
  • Tenderness when touching the abdomen

Byetta and Januvia pancreatic cancer

Pancreatitis is a known risk factor for pancreatic cancer, which is the fourth most common cause of cancer-related deaths in the United States. Pancreatic cancer is extremely dangerous, killing most patients within a year of diagnosis and almost all victims within five years. The average prognosis for most patients is a six to ten month survival period.

While the FDA is investigating the connection between Januvia side effects and pancreatic cancer, one study found that patients treated with Byetta or Januvia were almost three times as likely to develop the cancer as those given other types of therapy for their diabetes. This increased risk comes in addition to the already great risk of developing pancreatic cancer faced by diabetes patients.

Symptoms of pancreatic cancer include:

  • Upper abdominal pain that may radiate to the back
  • Jaundice (yellowing of the skin and the whites of the eyes)
  • Loss of appetite
  • Weight loss
  • Depression
  • Blood clots

Byetta and Januvia thyroid cancer investigated

Because the enzymes inhibited by Januvia fight cancer, Januvia carries a hypothetical risk of causing other cancers besides pancreatic cancer. One study showed a slightly elevated rate of reports of thyroid cancer in Januvia patients, but this result was not considered statistically significant and the study’s authors say that further tests are needed to confirm or rule out the risk of Januvia related thyroid cancer. This lack of adequate safety information about Januvia is likely to fuel legal allegations that Merck failed to perform adequate testing on the product before releasing it and marketing it as safe.

The same study raised even more concerns about side effects of Byetta, as finding showed Byetta patients more than four times as likely to develop thyroid cancer compared to patients using other diabetes medications.

Litigation over Byetta and Januvia

With millions of people taking the diabetes medication, serious Januvia side effects are guaranteed to result in lawsuits alleging product defect, inadequate testing, and failure to warn the public about the dangers of Januvia. Merck already faces 43 personal injury Januvia lawsuits in U.S. courts from plaintiffs alleging that they developed pancreatic cancer as a result of taking the drug.  Eli Lilly is being sued by an estimated 600 plaintiffs who are suffering adverse side effects of Byetta.  Tragically, pancreatic cancer kills so quickly that some of these plaintiffs may not live to see their day in court, and some have already requested an expedited hearing so they don’t have to spend their few remaining months awaiting trials. Their litigation may give way to a series of Byetta and Januvia wrongful death claims.