Victoza Side Effects

Victoza (liraglutide injection) is a once-a-day injectable medication for Type 2 diabetes. The most common side effects of the drug are gastrointestinal problems such as nausea, vomiting and diarrhea. In clinical trials, these reactions occurred in 5 percent or more of patients who took the drug.

In addition to common side effects, Victoza’s medication label warns about a few serious side effects. People with existing kidney problems who take the medication may experience worsening of kidney failure. The drug may increase the risk of pancreatitis and gallbladder disease. It also carries a black box warning — the FDA’s most serious warning — for the risk of thyroid cancer.

According to the U.S. Food and Drug Administration’s Adverse Events Reporting System (FAERS), there were 30,740 reports of adverse events associated with the medication from 2010 to Sept. 30, 2019. This included 10,967 serious cases, and 917 of those were deaths.

FAERS data is postmarketing data which means it comes from real-world clinical practice as opposed to clinical trials, where researchers carefully select patients to receive a drug.

Because FAERS is voluntary reporting, researchers say side effects are underreported. But it also means there is no way to verify that a drug actually caused the side effect. In the case of Victoza, the most reported side effect in clinical trials — nausea — is also one of the most reported side effects in FAERS.

The medication may have one desirable side effect for Type 2 diabetes patients: decreased appetite. People take in fewer calories because the drug decreases appetite and this may lead to weight loss.

In March 2013, an FDA Drug Safety Communication warned that several Type 2 diabetes drugs including Victoza may increase the risk of pancreatitis. The FDA also flagged some data that suggests precancerous changes to the pancreas.

Lawsuits over Victoza say the drug’s faulty formulation increased the chances of developing pancreatic cancer, and the drug’s manufacturer failed to adequately warn of the risk. The drug’s prescribing information does not include information on pancreatic cancer.

Though pancreatitis is a rare side effect of the medicine, the FDA still requires a warning on the drug’s medication label. Some studies made a connection between pancreatitis and Victoza’s active ingredient, liraglutide. Researchers also described some individual patient cases.

A review published in June 2015 in Diabetes Care looked at clinical trial data on liraglutide and pancreatitis. Researchers found more people on liraglutide suffered pancreatitis than people who took other diabetes drugs. People who took liraglutide had 2.1 times the risk compared to other diabetes drugs in the trials.

An earlier paper published in 2011 in the International Journal of Clinical Pharmacology reviewed eight clinical studies and found six cases of pancreatitis and five cases of cancer in patients who took liraglutide. Cancer types reported included pancreas, lung, thyroid, and epiglottis.

More recently, in a 2018 case report by Quesada-Vazquez and colleagues, researchers reported the case of a 44-year-old woman who had abdominal pain with nausea and vomiting. They examined her and determined she had pancreatitis from taking liraglutide at a dose used for weight loss.

Doctors admitted her to the hospital, discontinued the drug, and gave her intravenous fluids and painkillers. After four days, signs and symptoms of pancreatitis began to resolve.

Victoza has a black box warning for the risk of thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), a rare and difficult-to-treat type of thyroid cancer.

The drugmaker placed the warning on the medication based on animal studies that showed mice exposed to liraglutide developed tumors, and researchers don’t actually know how this will affect humans.

From 2010 to Sept. 30, 2019, FAERS received over 250 reports of various thyroid cancers in Victoza users, including 27 cases of MTC that included two deaths.

Dr. Michael A. Nauck and Nele Friedrich described the connection between liraglutide, as well as other medications in the same drug class, and thyroid cancer in the journal Diabetes Care in August 2013. Some mice and rats given injections of liraglutide had increased C-cell abnormalities that led to tumors.

The authors noted that human C-cells may not respond the same way. They looked at studies where humans received liraglutide for up to 52 weeks with doses ranging from 1.8 mg to 3 mg daily, and there was no indication that C-cells changed.

Still, authors could not say for sure that liraglutide did not cause thyroid cancer. They urged caution in people with a higher risk for thyroid cancer.

A November 2022 study found Victoza and other drugs in the same class were associated with an increased risk of all thyroid cancer and medullary thyroid cancer. The risk was the greatest after one to three years of treatment.

The medication label for Victoza states that patients with a history of medullary thyroid cancer or Multiple Endocrine Neoplasia syndrome type 2, a type of thyroid cancer, should not use the medication. Patients with a family history of thyroid cancer are also at high risk of developing thyroid tumors and should not use the medication.

Victoza’s drug label warns that clinical trials found some patients who took the drug suffered acute gallbladder disease. Most of these people required hospitalization and/or gallbladder removal.

According to the clinical trial data, 3.1 percent of the 4,666 patients who took Victoza suffered gallbladder disease compared to 1.9 percent of the 4,672 placebo-treated patients.

Researchers have theories about how the medication may affect the gallbladder. A 2018 study in Diabetes, Obesity and Metabolism showed liraglutide slowed the process of bile leaving the gallbladder. If the bile builds up in the gallbladder, it can cause inflammation and infection, a condition known as cholecystitis.

Several studies have shown that liraglutide and other medications in the same drug class may increase gallstone production.

A 2017 RxFiles Trial Summary of the Liraglutide: Cardiovascular (CV) Outcomes and Mortality in Patients with Type 2 Diabetes (T2DM) (LEADER) trial found there will be one extra case of gallbladder disease for every 100 patients who use Victoza.

Authors Rebecca Stan and colleagues said the LEADER trial was the largest and longest trial for liraglutide to date, but it only lasted 3.5 to 5 years and had weaknesses. People who dropped out of the trial because of severe adverse events were “censored,” or not included in final analysis, so trial researchers could have missed important side effects. Also, Novo Nordisk, Victoza’s manufacturer, funded the trial.