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Januvia & Janumet


Januvia and Janumet are prescription drugs that belong to a group of Type 2 diabetes drugs called incretin therapies. Studies link these drugs to an increased risk of pancreatitis and pancreatic cancer and a possible increase in thyroid cancer.

Januvia (sitagliptin) is an oral medication manufactured by Merck & Co. The drug was approved by the U.S. Food and Drug Administration (FDA) in 2006 and is one of the most popular Type 2 diabetes drugs on the market. In 2007, the FDA approved a variation of Januvia called Janumet, which is a combination of sitagliptin and metformin, and is also made by Merck.Januvia and Janumet are diabetes drugs. They can have serious side effects. Januvia is the top-selling brand in its class, and the drug allows Merck to tower above the competition with a large portion of the DPP-4 global market share with Januvia alone. With two million prescriptions written in 2011, analysts expected the drug to eventually produce multi-billion dollar sales numbers. They were right. Januvia brought in about $6 billion in 2014. Merck stands to benefit from the patent on the drug until 2022 and is developing a once-a-week version of Januvia. Januvia is now prescribed to be taken by mouth once a day. In clinical trials Januvia proved to be effective in controlling blood sugar levels. However, there are also reports of serious side effects, including acute pancreatitis, pancreatic cancer and thyroid cancer, which caused Januvia users to file lawsuits against Merck. In legal proceedings, plaintiffs accused Merck of negligence and concealing the risks of significant side effects.

How Does Januvia Work?

Januvia is designed to work with other Type 2 diabetes medications, like Byetta, to increase their effectiveness. It is not meant to treat people with Type 1 diabetes. Januvia helps lower blood sugar in two ways. It helps the body increase insulin to stabilize blood sugar and decrease sugars that are made in the liver. It is a part of the class of diabetes medications called DPP-4 inhibitors. DPP-4 is a protein made by the body that plays a role in glucose metabolism. The process works like this: After a person eats and blood sugar rises, hormones called incretin hormones are released from intestinal cells. Incretin stimulates pancreatic cells called beta cells to release insulin to metabolize sugar and signals the liver to stop making excess sugar. In people without diabetes, DPP-4 breaks down incretin to keep blood sugar and insulin levels balanced. For people with diabetes, too much sugar is already in the blood. Januvia blocks DPP-4, allowing incretin to stay in the blood longer and to continue stimulating the pancreas into make more insulin to remove excess sugar. People who have excess ketones in the blood or urine – a condition known as diabetic ketoacidosis – should not take Januvia or Janumet.

Serious Side Effects

The most serious side effects associated with Januvia and Janumet are acute pancreatitis, pancreatic cancer and thyroid cancer. In 2011, the FDA received almost 200 reports of acute and chronic pancreatitis linked to Januvia and Janumet – some of which were fatal. In 2015, the FDA warned Januvia and Janumet could cause severe joint pain.


Pancreatitis is an inflammation of the pancreas. It can cause the body's digestive enzymes to attack the pancreas. In severe cases, the disease can cause tissue damage, infection, cyst formation and bleeding. The damage can spread to other organs like the heart, kidneys and lungs, and the mortality rate is 10 to 30 percent.
The symptoms of pancreatitis include:
Abdominal pain that may radiate to the back Increased pain while eating or bending forward
Nausea Vomiting
Fever Rapid heartbeat
Cases of pancreatitis associated with Januvia and Janumet tend to be acute, meaning the disease occurs quickly and over a short period of time, and it can be fatal. A UCLA clinical study published in the journal Gastroenterology revealed that taking Januvia increases the risk of pancreatitis six-fold, and cases usually develop in less than two months. Nearly 100 cases of acute pancreatitis caused by Januvia, including necrotizing pancreatitis, were reported to the FDA between 2006 and 2009. Necrotizing pancreatitis occurs when digestive hormones produced by the pancreas begin to digest the pancreatic tissue, which can lead to death. In 2009, the FDA issued a safety alert that linked sitagliptin, the active ingredient in Januvia and Janumet, to acute pancreatitis. There were no safety studies conducted in people who have a history of pancreatitis, and the agency warned that it is not known whether these people are at an increased risk if they take sitagliptin. Pancreatitis can also lead to pancreatic cancer. The FDA issued an updated alert in 2013, saying it was still investigating Januvia and similar drugs for evidence that they caused pancreatitis or pancreatic cancer.

Pancreatic Cancer

Januvia and Janumet are also linked to pancreatic cancer. Pancreatic tumors can grow without symptoms and may not be detected until the cancer reaches a later stage. People taking sitagliptin have more than double the risk of developing pancreatic cancer, according to the UCLA study. The risk of developing cancer increases the longer someone takes Januvia or Janumet. Dr. Peter Butler, the study's lead investigator, said it can be difficult to discover the extent of the damage done to the pancreas without removing it and examining it. As a result, pancreatic cancer may be diagnosed late. The American Cancer Society said the average rate of survival is 18 to 20 months, and the overall five-year survival rate is four percent. In a 2015 review of current literature, researchers summarized the results of FDA adverse event reports. They found a high incidence of pancreatic cancer in patients who took DPP-4 inhibitors like Januvia and Janumet. The researchers concluded further studies were needed, but the benefits of the drugs might outweigh the risks.

Thyroid Cancer

There have also been reports of patients developing thyroid cancer after taking Januvia. The UCLA study found a very minor increase in thyroid cancer, with only two cases reported out of the sample group. The 2015 analysis of FDA adverse event reports also found an increase in thyroid cancer in people who took incretin-based therapies like Januvia, although glucagonlike peptide-1 (GLP-1) receptor agonists like Victoza had a much higher incidence of thyroid cancer. According to the ACS, the death rate of thyroid cancer is relatively low compared to other cancers. However, it can cause many serious side effects including swelling of the neck, pain, voice changes and hoarseness, trouble swallowing or breathing, and a constant cough.
In addition to pancreatitis, pancreatic cancer and thyroid cancer, Januvia and Janumet are linked to a number of other side effects, including:
Hypoglycemia Abdominal pain
Nausea Diarrhea
Constipation Vomiting
Elevated liver enzymes Swelling of hands or legs
Headache Upper respiratory infection
Stuffy or runny nose Sore throat

Side Effects of Janumet

Because Janumet is made with metformin, it carries a black-box warning about lactic acidosis. This condition occurs when metformin builds up in the blood and causes lactic acid to accumulate in the bloodstream. Symptoms of lactic acidosis include weakness and nausea. People who suffer from lactic acidosis should seek medical care immediately. In addition, Januvia and Janumet increase the risk for kidney problems that may require dialysis.

Januvia Lawsuits

Some people who took Januvia and Janumet suffered from severe side effects like pancreatitis and pancreatic cancer that may have led to death. As a result, patients and their families filed lawsuits against Merck. Guy Riley filed a lawsuit on behalf of his wife Kathleen in October 2012. His lawsuit alleges that Merck and Amylin and Eli Lilly – the manufacturers of another diabetes drug also taken by Kathleen called Byetta – concealed their knowledge of dangerous side effects. Kathleen Riley began taking Januvia in 2006, and in 2009 she was diagnosed with pancreatic cancer. She later died from the disease. Riley's lawsuit claims that defendants failed to warn about side effects, and that despite knowing about the risk of pancreatic cancer, the drug manufacturers continued to aggressively market and sell defective products. If you or a loved one took Januvia or Janumet and suffered from dangerous side effects like pancreatitis or pancreatic cancer, Drugwatch can help. Our patient advocates can answer your questions about treatment and explain your legal options.