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The injectable Type 2 diabetes drug Victoza works by stimulating insulin production. The drug may be linked to serious side effects, including pancreatitis, thyroid cancer and pancreatic cancer.

Victoza (liraglutide) is a once-a-day drug manufactured by Novo Nordisk. It was approved by the Food and Drug Administration (FDA) in January 2010. Victoza is similar to Amylin Pharmaceuticals’ injectable diabetes drug Byetta (exenatide) in that it aims to lower blood sugar by mimicking a hormone called GLP-1. As of March 2013, almost 1 million Americans took Victoza or another GLP-1 mimetic. Victoza packaging Novo Nordisk reported $475.8 million in Victoza sales in the first quarter of 2013, up 36 percent from a year earlier. Victoza is the company’s hottest product by far. Worldwide Victoza sales for 2012 topped out at $1.7 billion, accounting for more than 12 percent of Novo Nordisk’s full-year sales. A month’s supply of Victoza, at the average dose, costs about $500 without insurance; in comparison, Byetta costs about $170 per month. Celebrity chef Paula Deen was a spokeswoman for Victoza until June 2013, when Novo Nordisk cut ties with her after she admitted having used racist language. She originally signed a $6 million, two-year contract. Though it is effective in controlling blood sugar, Victoza may be linked to dangerous side effects, including pancreatitis and thyroid cancer. Product liability lawsuits are expected to follow.

How Does Victoza Work?

Victoza works by stimulating natural insulin production in the pancreas, and is used alongside a healthy diet and exercise routine. Victoza may be prescribed alongside oral diabetes medications such as Actos, Avandia, Amaryl (glimepiride) and metformin, but may impact the absorption of these drugs since it delays gastric emptying. Victoza is not an insulin product; it is 97 percent similar to a bodily hormone called GLP-1 (glucagon-like peptide-1). This hormone affects the liver, pancreas and gut and helps control glucose, insulin and gastric emptying. When a person eats, the small intestine releases this hormone, which helps the pancreas release the appropriate amount of insulin to help regulate blood sugar. More specifically, GLP-1 activates pancreatic cells called beta cells that make insulin. By the time most people are diagnosed with Type 2 diabetes, about half of their beta cells aren’t working properly. Patients take Victoza once a day inserting the prescription pen into their thigh, upper arm or stomach. Their doctor teaches them how to use the Victoza pen. The pre-filled 32-gram pens can last up to 30 days or more, depending on the daily dosage (0.6 mg, 1.2 mg or 1.8 mg.

Clinical Studies

During one 52-week clinical trial, 6,090 patients who received Victoza once a day as a stand-alone treatment saw a 1.1 percent decrease in A1C (which measures the average glucose concentration over a two- to three-month period) when taking 1.8 mg of the drug; patients taking 1.2 mg averaged a 0.8 percent decrease. Patients lost an average 5.5 pounds with a 1.8 mg dosage; for patients taking a 1.2 mg dosage, the average weight loss was 4.6 pounds. Another 52-week trial found that patients experienced about a 20 percent reduction in FPG (fasting glucose level) when taking 1.8 mg of Victoza daily, while blood-glucose levels in patients taking 1.2 mg dropped about 16 percent. The FPG levels began to decline within two weeks.

Side Effects

The possible side effects of Victoza are pancreatitis and thyroid tumors, both of which can be fatal. The Institute for Safe Medication Practices (ISMP) reported that the FDA's clinical safety reviewer originally voted against approving the drug because of its link to thyroid tumors, insufficient study to rule out increased heart attack and stroke risk, as well as an increased risk for pancreatitis. In 2011, the FDA published a warning that doctors weren't fully aware of thyroid risks associated with Victoza. That notice also mentioned that clinical trials suggested an increased risk of pancreatitis in Victoza patients.
Possible side effects of Victoza:
Pancreatitis Thyroid tumors
Low blood sugar Severe allergic reactions
Kidney problems/failure
The most common side effects, reported by more than 5 percent of patients using Victoza, are diarrhea, nausea, constipation and headache.


Pancreatitis occurs when the pancreas swells and becomes inflamed. Severe cases of pancreatitis can require hospitalization, and can be fatal. Victoza has not been studied in patients who have a history of pancreatitis, but the medication guide warns that pancreatitis is one of the severe side effects. The Institute for Safe Medication Practices (ISMP) reported that within the first nine months after approval, the FDA received reports of more than 100 cases of acute pancreatitis and pancreatitis linked to the drug. Only one other drug in the same class has more reported cases of pancreatitis: Byetta. The ISMP contacted Novo Nordisk about its findings, and the company responded by pointing out that people with diabetes already have a 2.8-4.2 times higher risk of pancreatitis than those without diabetes. Further, the company said it already has an FDA-approved plan to educate patients and doctors about the risks of Victoza, including pancreatitis.
Pancreatitis symptoms include:
Fever Yellowing skin
Severe chronic abdominal and/or back pain Sweating
Vomiting Swelling in the abdomen
According to the FDA safety alert posted in June 2011, Novo Nordisk reported more patients suffered from pancreatitis while taking Victoza in clinical trials than patients treated with comparable drugs. According to a 2012 study by Franks, et al. published in the Annals of Pharmacotherapy, a literature survey found 11 cases of pancreatitis reported from patients taking Victoza, with one case resulting in death. In March 2013, the FDA announced it had received data from unpublished studies pointing to a possible link between pancreatic cancer and drugs like Victoza, Januvia and Byetta. Researchers studied a small sampling of pancreatic tissue samples from patients who died of unspecified causes and were treated with an incretin mimetic. The data showed pre-cancerous cells in the pancreas. Then in July 2013, the European Medicines Agency (EMA) announced that it did not feel the studies presented enough data to conclude incretin mimetics increase the risk of pancreatitis and pancreatic cancer. The FDA agreed with the EMA and said it would not change the official labeling. However, the FDA’s investigation is ongoing.

Thyroid Cancer

Novo Nordisk found that Victoza causes tumors of the thyroid gland in rats, including malignant tumors. Since the drug is fairly new and since thyroid cancer is rare in humans (with just 600 U.S. cases reported per year), the FDA has stated that it’s difficult to say whether the drug can cause thyroid cancer in humans.
Thyroid cancer symptoms include:
Difficulty swallowing Hoarseness
Swelling/lump in the neck Shortness of breath
Victoza does come with a black-box label that warns of the risk of thyroid C-cell tumors and possible thyroid cancer. The black box warns that Victoza (liraglutide) “causes thyroid C-cell tumors at clinically relevant exposures in rodents,” and goes on to state that it’s unknown whether Victoza causes these tumors, including cancer (medullary thyroid carcinoma, or MTC), in humans.

Additional Warnings

The FDA also warns people with or a family history of thyroid (especially medullary thyroid) cancer or Multiple Endocrine Neoplasia syndrome Type 2 against taking Victoza.
Patients with certain medical histories should speak to their doctor, since Victoza may be contraindicated for the following conditions:
Gallstones Pancreatitis
High triglyceride levels Alcoholism
Severe stomach problems and/or issues with digestion Liver or kidney problems
Pregnancy or a plan to become pregnant Breastfeeding or plans to breastfeed

Victoza Lawsuits

The makers of Byetta and Januvia are facing numerous lawsuits that claim the drugs caused pancreatitis and pancreatic cancer. Because Victoza is in the same class of drugs, similar lawsuits against Novo Nordisk are expected to follow. Patients injured by Victoza are likely to claim that they were not warned of the serious side effects. There is a petition to have all incretin mimetic lawsuits consolidated into a single federal multidistrict litigation (MDL). The petition quotes Dr. Sidney Wolfe, director of the health and research group at the nonprofit Public Citizen: “Although we have previously petitioned the FDA to ban Victoza (liraglutide) because of concerns about pancreatic disease and thyroid cancer, it is clear that all of the drugs in this family are associated with an increased risk of pancreatic cancer and it is likely that they will all have to be removed from the market.”