Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Entyvio (Vedolizumab). If you are concerned about side effects, discuss the risks and benefits of Entyvio (Vedolizumab) with your doctor.

The following side effects have been reported by at least 1% of people taking Entyvio (Vedolizumab). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• fatigue
• Fever
• headache
• joint pain
• nausea

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• cold or flu symptoms (e.g., sore throat, cough, runny nose)
• signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a Anaphylaxis (severe allergic reaction) (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of an infusion reaction (e.g., rash, itching, feeling hot, rapid, pounding heartbeat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Entyvio (Vedolizumab).

Each single-use vial containing a white-to-off-white cake contains 300 mg of Entyvio (Vedolizumab). Nonmedicinal ingredients: L-histidine, L-histidine monohydrochloride, L-arginine hydrochloride, sucrose, and polysorbate 80.

Do not take Entyvio (Vedolizumab) if you:

• are allergic to Entyvio (Vedolizumab) or any ingredients of the medication
• have severe, active infections such as blood infections
• have active infections that develop when your immune system is weakened such as Tuberculosis or cytomegalovirus

There may be an interaction between Entyvio (Vedolizumab) and any of the following:

• bacillus Calmette-Guérin (BCG)
• Baricitinib
• Cladribine
• Denosumab
• echinacea
• Fingolimod
• Leflunomide
• Natalizumab
• Pimecrolimus
• Roflumilast
• Tacrolimus
• Tofacitinib
• Trastuzumab
• tumour necrosis factor (TNF) inhibitors (e.g., Adalimumab, certolizumab, Etanercept, Infliximab, Lenalidomide, thalidomide)
• vaccines

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Entyvio (Vedolizumab). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Entyvio (Vedolizumab).

Allergic reactions: In rare cases, some people may develop a severe allergic reaction to Entyvio (Vedolizumab). These reactions may not occur with the first infusion of the medication, and may happen with future doses of Entyvio (Vedolizumab). Your health care provider will monitor you while you are receiving Entyvio (Vedolizumab) by infusion. Signs of an allergic reaction include a severe rash, Hives, swollen face or throat, difficulty breathing, lightheadedness, or dizziness. If any of these occur, contact your doctor immediately.

Infections: Entyvio (Vedolizumab) may increase the risk of developing an infection, including serious infections such as sepsis, pneumonia, and tuberculosis. Before starting Entyvio (Vedolizumab) treatment, your doctor may test to see if you have tuberculosis. If you notice signs of an infection such as fever, chills, pain, swelling, coughing, or pus, contact your doctor as soon as possible. Entyvio (Vedolizumab) should also not be started while you have an active infection.

Liver function: Entyvio (Vedolizumab) can cause decreased liver function. If you have liver problems, discuss with your doctor how Entyvio (Vedolizumab) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Entyvio (Vedolizumab), and whether any special monitoring is needed. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Progressive multifocal leukoencephalopathy (PML): Although there have not been reports of PML after using Entyvio (Vedolizumab), it has been reported with other medications in the same family. PML is a rare disorder that causes nerve damage in the brain. If you experience memory loss, vision loss, trouble thinking, or difficulty walking, contact your doctor immediately.

Vaccines: Live vaccines (e.g., BCG, yellow fever) are not recommended for people taking Entyvio (Vedolizumab). Talk to your doctor if you need any vaccinations while taking Entyvio (Vedolizumab).

Pregnancy: Entyvio (Vedolizumab) should not be used during pregnancy. If you are of childbearing age, effective birth control should be used while you are being treated with Entyvio (Vedolizumab) and for at least 18 weeks after your final treatment. If you become pregnant while taking Entyvio (Vedolizumab), contact your doctor immediately.

Breast-feeding: Entyvio (Vedolizumab) passes into breast milk. If you are a breast-feeding mother and are taking Entyvio (Vedolizumab), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Entyvio (Vedolizumab) have not been established for children.