Other Health Conditions

What Patients Should Know About Renflexis (Infliximab-abda)

Ankylosing spondylitis patient on Renflexis

Renflexis is a prescription drug used to treat a range of autoimmune disorders. Autoimmune disorders occur when the immune cells attack healthy cells, mistaking them for foreign particles (bacteria or viruses). 

Renflexis is a biological product belonging to a family of medicines called tumor necrosis factor (TNF) blockers or anti-TNF agents. Biological products, or simply biologics, are made using living cells. 

The active ingredient in Renflexis—infliximab-abda— is a biosimilar to infliximab (brand name: Remicade). A biosimilar means that Renflexis is almost identical to Remicade in terms of its indication for use, recommended dosage, strength, preparation, and administration for use. Other biosimilars to Remicade include:

  • Inflectra (infliximab-dyyb)
  • Avsola (infliximab-axxq)
  • Ixifi (infliximab-qbtx)

The 4-letter suffix following the non-proprietary name of the drug (infliximab in this case) is unique to each biological product. This helps healthcare professionals distinguish between different branded versions of a biologic. 

How Is Renflexis Supplied and Used?

Renflexis is supplied as a single-dose vial with the appearance of a white powder form.  Each vial contains 100 mg of infliximab-abda. This medication will be administered intravenously (IV) as directed by your physician. 

Your doctor will calculate the required dose and number of vials needed based on your weight. To prepare Renflexis for administration, the nurse will mix one vial in 10 ml of sterile water for injection and allow the solution to stand for 5 minutes. Then, they will dilute the solution with sterile 0.9% NaCl injection so that the final volume is 250 ml. 

Finally, the intravenous infusion is administered over a period of 2 hours or more. Infusions should begin within 3 hours after dilution, and any unused portion of the solution should be discarded appropriately. 

How Does Renflexis Work?

As mentioned above, an autoimmune disorder causes a person’s immune system to overproduce a pro-inflammatory protein called tumor necrosis factor-alpha (TNF-ɑ). High levels of TNF-ɑ in the body can contribute to symptoms such as joint pain/stiffness, muscle aches, rashes, fever, and loss of appetite.

Renflexis blocks the action of TNF-alpha, leading to a decreased level of these proteins in the body. As a result, this can lead to the reduction of the signs, symptoms, and severity of the patient’s condition. 

What Is Renflexis Used to Treat?

Renflexis has been FDA-approved to treat several autoimmune disorders in adults and children 6 years and older. 


  • Crohn’s disease (CD). CD is a long-term condition that causes inflammation and irritation in the digestive tract, particularly the small intestine and upper part of the colon. Renflexis helps to improve the signs and symptoms of this condition. The goal of this therapy is to help induce and maintain a symptom-free state. 
  • Ulcerative colitis (UC). Patients with UC will mainly experience inflammation and irritation in the colon (the longest part of the large intestine). Renflexis helps to improve the signs and symptoms of this condition. The goal of this therapy is to help induce and maintain a symptom-free state.
  • Rheumatoid arthritis (RA). RA is a weakening condition that can cause joint pain, swelling, and stiffness. Renflexis helps to reduce the signs and symptoms, delay joint damage, and improve overall joint function.  
  • Ankylosing spondylitis. Ankylosing spondylitis (a form of arthritis) affects the spine. Renflexis helps to reduce the signs and symptoms and delay joint damage.  
  • Psoriatic arthritis. Psoriatic arthritis can occur in some people with psoriasis (visible patches of thick red skin and silvery scales present on the skin). Renflexis helps to reduce the signs and symptoms, delay joint damage, and help improve overall joint function.
  • Plaque psoriasis. Renflexis improves symptoms in adults with chronic severe plaque psoriasis, a skin disease that causes scaly and painful skin patches (plaques).


Renflexis is FDA-approved to treat children 6 years and older who have been diagnosed with Crohn’s disease and ulcerative colitis. 

What Are the Side Effects of Renflexis in Adults?

Side effects are generally mild, but can be severe or life-threatening. 

Renflexis does carry a U.S. Boxed Warning, stating that this medication can cause serious infections and certain types of malignancy in both adults and children. Patients who have weakened immune systems, active tuberculosis (TB), or a history of recent invasive infections should consult with their doctor prior to starting therapy. This medication can also lead to certain types of lymphoma or another rare type of T-cell lymphoma.

Common Side Effects

  • Sinus infections (stuffy nose, breathing difficulty, and pain around the eyes)
  • Sore throat
  • Headache
  • Coughing
  • Stomach pain or diarrhea
  • Feeling tired or weak 

Talk to your doctor or pharmacist if any of these side effects worsen or persist. 

Severe Side Effects

Call your doctor immediately if you experience any serious side effects. You should call 911 if you think your symptoms are life-threatening and seek medical attention immediately. The severe side effects with their symptoms are listed below:

Renflexis side effect

Serious infections

  • Fever
  • Feeling very tired
  • Coughing
  • Flu-like symptoms
  • Warm, red, or painful skin

Hepatitis (liver inflammation) or liver failure

  • Pain on the upper right side of the stomach
  • Dark brown urine
  • Exhaustion
  • Fever
  • Jaundice (yellowing of skin and eyes)

New or worsening heart failure

  • Shortness of breath
  • Swelling in the ankles or feet
  • Sudden weight gain

Heart attack, ischemia (decreased blood flow to the heart), or irregular heartbeat

These problems may occur within 24 hours after starting the infusion. 

  • Chest discomfort or pain
  • Arm pain
  • Stomach pain
  • Shortness of breath
  • Anxiety
  • Lightheadedness
  • Dizziness
  • Fainting
  • Sweating
  • Nausea and vomiting
  • Irregular heartbeat
  • Feelings of a pounding heart

Blood problems

  • Persistent fever
  • Easy bruising or bleeding
  • Pale skin

Problems affecting the brain, spinal cord, and nerves

  • Vision changes
  • Seizures
  • Tingling or numbness that can affect any part of the body

Lupus-like syndrome

  • Persistent chest pain or discomfort
  • Shortness of breath
  • Joint pain
  • Rash on your cheeks or arms, which often gets worse in the sun

Infusion-related Reactions

These symptoms may occur during or up to 2 hours after an infusion:

  • Shortness of breath
  • Flushing
  • Headache
  • Rash
  • Chest pain
  • Seizures
  • Low or high blood pressure

Allergic Reactions

Seek emergency medical help if you experience the following:

  • Chest pain
  • Hives
  • Shortness of breath
  • High or low blood pressure
  • Fever
  • Chills

Renflexis Side Effects on Children

When used for ulcerative colitis, the risk of infections appears to be higher in children than adults. In addition, the side effects can differ among children and adults who take the drug for Crohn’s disease. 

Clinical trials show that the following side effects are more common in children:

  • Anemia (low red blood cell levels)
  • Leukopenia (low white blood cell levels)
  • Flushing
  • Viral infection
  • Neutropenia (low levels of specific immune cells)
  • Bone fracture
  • Bacterial infection

Renflexis Dosage

Your doctor will prescribe Renflexis doses based on your:

  • Diagnosis
  • Body weight 
  • Response to treatment
  • Other current health conditions

Treatment regimens may be discontinued if you develop a serious infection, show no response to treatment, or have a serious allergic or infusion-related reaction. Your doctor will test you for tuberculosis and hepatitis B prior to and during therapy. 

The recommended doses are outlined below: 

Adult Dosage

  • Crohn’s disease: Calculate dose at 5 mg/kg of patient’s body weight given at 0, 2, and 6 weeks, then every 8 weeks. If the dose is effective initially but no longer effective after a while, the dose may be increased to 10 mg/kg. 
  • Ulcerative colitis: Calculate dose at 5 mg/kg at 0, 2, and 6 weeks, then every 8 weeks.
  • Rheumatoid arthritis (when given together with methotrexate): Calculate dose at 3 mg/kg at 0, 2, and 6 weeks, then every 8 weeks. The dose may be increased to 10 mg/kg every 4 weeks, if therapeutic effects are not achieved.
  • Ankylosing spondylitis: Calculate dose at 5 mg/kg at 0, 2, and 6 weeks, then every 6 weeks.
  • Psoriatic arthritis and plaque psoriasis: Calculate dose at 5 mg/kg at 0, 2, and 6 weeks, then every 8 weeks.

Child Dosage (6 Years or Older)

Crohn’s disease and ulcerative colitis: Calculate dose at 5 mg/kg at 0, 2, and 6 weeks, then every 8 weeks.

Use in Pregnancy and Lactation

Those who are pregnant or planning to get pregnant should discuss with their doctor about the risks and benefits of treatment. 

Currently available data have not safely established a clear association between Renflexis use during pregnancy and adverse pregnancy outcomes, such as low, spontaneous abortion, birth defects, premature delivery, or stillbirth. In addition, animal studies have found no evidence of problems with fetal toxicity.

Renflexis can cross the placental barrier and has been found in infants up to 6 months following birth. Renflexis can weaken the infant’s immunity; therefore, parents should avoid getting a child vaccinated with live vaccines (e.g., rotavirus vaccine) until they reach the age of 6 months. 

Breast milk may also contain low levels of infliximab. Infliximab is degraded in the digestive tract and therefore, it is unlikely that infliximab in breast milk can affect an infant’s immunity or development. 

How Much Does Renflexis Cost?

The amount you pay for Renflexis treatment can vary, depending on your insurance plan, geographical location, and pharmacy. Contact your insurance provider to find out if your plan covers Renflexis or if you need prior authorization.

This information is not a substitute for medical advice or treatment. Talk to your doctor or healthcare provider about your medical condition prior to starting any new treatment. AmeriPharma™ Specialty Care assumes no liability whatsoever for the information provided or for any diagnosis or treatment made as a result, nor is it responsible for the reliability of the content. AmeriPharma™ Specialty Care does not operate all the websites/organizations listed here, nor is it responsible for the availability or reliability of their content. These listings do not imply or constitute an endorsement, sponsorship, or recommendation by AmeriPharma™ Specialty Care. This webpage may contain references to brand-name prescription drugs that are trademarks or registered trademarks of pharmaceutical manufacturers not affiliated with AmeriPharma™ Specialty Care.

Dr. Rachel Chang, PharmD was born and raised in Hawaii. She received her degree from Marshall B. Ketchum University in 2022, where she graduated with cum laude honors. The most rewarding part of her job is the connections she makes with each patient. She enjoys speaking with each patient and helping them achieve the best treatment possible. In her free time, she likes spending time with her family, traveling, fishing, and mountain biking.