An infusion is similar to an intravenous (IV) injection, where doctors administer medications directly into the bloodstream. People with ulcerative colitis (UC) can receive medicated infusions to manage their condition.

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The recommended medical or surgical treatment for UC will vary, depending on the severity of the condition and frequency of flares.

Some people may receive infusions containing medications regularly, while others may not need them as often or will take oral medications.

This article explores what an infusion is and how it treats UC. We also examine how the therapy works, the drugs used, potential side effects, and whether Medicare covers infusion therapy.

Infusion therapy, or IV infusion, involves receiving medication or fluids through a needle or catheter.

The catheter allows doctors to administer multiple doses of medicated infusions when necessary. This also means that medical professionals do not have re-inject a person every time they receive a dose.

Some people with UC receive medicated infusions regularly to help them manage their conditions.

Other people may need infusions to replenish nutrient levels, such as iron, or prevent dehydration.

Infusion therapy may take place in a variety of settings, including:

  • clinics
  • hospitals
  • pharmacies
  • at home

Doctors administer different drugs for medicated infusions when treating people with UC.

People should speak with their gastroenterologist to explore the different treatment options, alongside infusions.

Learn about medication and other options for treating UC here.

The Food and Drug Administration (FDA) approved Remicade to treat inflammatory bowel disease (IBD) in 1998.

IBD refers to several conditions that affect the gut, including UC and Crohn’s disease.

Infliximab is a manufactured antibody made of living cells and is a type of medication called a biologic. It works by targeting a protein called tumor necrosis factor-alpha (TNF-alpha). The body naturally creates this protein and helps the immune system fight infections.

However, if the body produces too much TNF-alpha, it can damage the gut lining and potentially cause the inflammation associated with IBD.

Infliximab binds to TNF-alpha proteins, blocking their harmful effects and reducing intestinal inflammation.

People on biologic medications via infusion therapy receive this medication at regularly scheduled intervals determined by the type of medication and disease severity.

Read more about biologics for UC here.


Doctors usually administer infliximab infusions in outpatient facilities due to the potential risk of reaction.

An adult or child can receive 5 milligrams (mg) of infliximab for every kilogram (kg) of body weight.

Doctors usually prescribe the medication for 12 months unless it is not working for a person.

Find out more about Remicade dosage here.


UC and Crohn’s disease have the same recommended dosing for adults.

A person will receive infusions at weeks 0, 2, and 6. The first infusion usually takes an hour, and doctors will continue monitoring people for any reactions afterward.

If people respond well to the treatment, doctors will put them on maintenance dosing of 5mg/ kg of an infusion every 8 weeks.

Some people may be able to administer their infusions at home over time, but a person should discuss this option with their doctor.

Learn more about infusions for Crohn’s disease here.


Current research suggests that infliximab is very effective at treating IBD.

However, if infliximab does not relieve symptoms or becomes less effective over time, a doctor may increase the dosage or frequency of the infusions. They will base these changes on:

  • a person’s symptoms
  • whether the blood test results indicate inflammation
  • the levels of medication in the blood

Although anti-TNF agents have an initial effect on symptoms, researchers have demonstrated a risk of secondary non-response or loss of response in 23–46% of people receiving infliximab.

People should speak with their IBD nurse for more information on Remicade infusions.

Read more about IBD here from our dedicated hub.

Side effects

A person may have an acute or delayed infusion reaction with infliximab. These may occur in the first 24 hours of infusion.

People may also experience anaphylaxis, a serious allergic reaction, and a medical emergency.

Anyone experiencing anaphylaxis must seek medical attention immediately. However, most individuals experience a nonallergic or an anaphylactoid reaction.

If doctors suspect a person may have an allergic reaction, they will administer the infusion in a hospital setting or discontinue the drug for this individual.

The most common side of anti-TNF medications is the increased risk of infections. These are usually mild. However, immunocompromised people may be at an increased risk of serious infections.

Before starting therapy, people undergo tests to detect latent tuberculosis (TB) and chronic hepatitis B infection. A rare side effect of this medication is that it may also elevate liver enzyme levels.

People should speak with their IBD nurse to discuss any concerns about side effects.

Find out more about Remicade’s side effects here.

Anti-integrin therapy is another example of biological medication. It targets molecules that contribute to the development of intestinal inflammation.

Doctors may prescribe this treatment for people with severe IBD who have not responded to other medications. Examples of this treatment include Tysabri (natalizumab) and Entyvio (vedolizumab).

This therapy prevents lymphocytes, a type of white blood cell that causes inflammation, from binding to the gastrointestinal tract lining.

Learn more about lymphocytes here.

Dosage and timing

Doctors administer anti-integrin medications through IV infusion. An example dosage may be 300 mg of vedolizumab over 14 weeks at scheduled intervals.

The most suitable frequency of anti-integrin IV infusions may vary between people.

A gastroenterologist will recommend the infusion schedule based on the severity of the disease.

Read more about the dosage of vedolizumab (Entyvio) here.


Based on 2018 research, the different drugs discussed above each have their efficacy for treating UC:


The number of people showing sustained clinical remission at both week 8 and week 12 was higher than the placebo group. The United States is the only country to approve natalizumab for moderate-to-severe IBD.


This drug demonstrated an effect against moderate-to-severe UC at week 6 and week 52. The FDA and European Medicines Agency approve this drug to treat moderate-to-severe IBD.

More research and clinical trials of anti-integrin drugs are needed to demonstrate their efficacy and associated adverse effects for people with IBD.

Learn more about biologics for UC here.

Side effects

Biologics suppress parts of the immune system and increase the risk of infections. People should discuss with their doctors how to avoid this and prevent serious infections.

Find out more about the side effects of natalizumab (Tysabri) here.

Cyclosporine is an immunosuppressant medication that reduces the activity of the immune system.

Dosage and timing

Doctors administer this medication as an infusion, and treatment will usually continue for around 7 days. People usually receive a 2 mg/kg per day IV regimen.

This drug treats milder cases of UC and tends to relieve symptoms within 1–2 weeks.

Learn more about treatments and medications for UC.


The 2020 research data showed a significantly higher colectomy-free survival rate with infliximab than cyclosporine. However, both drugs are safe for the treatment of UC.

Read more about ulcerative colitis colectomy here.

Side effects

Side effects of intravenous cyclosporine can include:

Cyclosporine may also increase the risk of lymphoma (skin cancer). This risk may be higher if a person takes other medications that decrease immune system functioning. People should tell a doctor if they take any of these medications.

Cyclosporine may also cause high blood pressure and kidney damage.

People should speak with their doctor to discuss these possible risks and ways to avoid them.

Find out more about cyclosporine here.

Corticosteroid medications are strong anti-inflammatory drugs to relieve symptoms in the short term. People can take this drug orally, as an enema, or as an infusion.


In cases of severe acute UC, people may receive steroids via infusion in the hospital. Intravenous steroids typically work within 4–10 days.


In a large-scale 2015 study undertaken in China, doctors initially treated people with oral corticosteroids (prednisone 40–60 mg per day or equivalent) or intravenous corticosteroids (hydrocortisone 200–400 mg per day or equivalent).

Overall, people showed short-and long term clinical responses to the treatment.

However, 20–30% of people with acute symptoms of IBD will not respond to treatment with steroids.

Learn more about corticosteroids for UC.

Side effects

People receiving IV hydrocortisone may experience side effects. A person should speak with a doctor if they experience any of the following:

Read more about prednisone for UC here.

A doctor may prescribe oral antibiotics or administer them via IV infusion to treat UC and Crohn’s disease.

A gastroenterologist recommends the appropriate length of time a person should take antibiotics based on the severity of the infection.


Two meta-analyses from 2016 research associated antibiotic therapy with a modest improvement in clinical symptoms.

Doctors must define the indications for antibiotics for IBD to reduce unnecessary treatment that may lead to increased antibiotic resistance.

More large sample-sized studies are needed to better understand the role of antibiotics in IBD.

Learn more about medications to avoid with UC here.

Side effects

Mild side effects of antibiotics include:

Some people may experience an allergic reaction to antibiotics.

In most cases, the allergic reaction is mild to moderate and can take the form of:

However, if a person experiences a severe reaction, they must consult medical attention immediately.

Read more about the side effects of antibiotics here.

People with IBD often have vitamin or mineral deficiencies due to the digestive system’s inability to absorb nutrients. These include:

Other recommended vitamins include:

Nutritionists may recommend dietary changes or supplements to boost digestive health. Another option is also receiving these vitamins via infusion.

Research demonstrates that intravenous iron infusions might offer an alternative for people who find oral tablets ineffective or if they are unable to tolerate them.

Learn more about vitamins, minerals, and supplements from our dedicated hub here.

Side effects

People should use high doses and long-term supplementation with zinc with caution, as there is a risk of toxicity.

Zinc can interfere with iron and copper absorption and exacerbate deficiencies. In turn, calcium or folate supplementation can reduce zinc absorption.

People should speak with a nutritionist to ensure they are on the correct dosage to reduce any risks of side effects.

Find out more about the risks of taking too much zinc here.

According to the Crohn’s & Colitis Foundation, most health insurance plans in the United States cover infusion therapy.

However, some plans specify which medications they cover and where people can receive them, limiting options for some people.

For example, if doctors administer Remicade through an outpatient service, Medicare will likely cover the infusions. However, if a person receives the infusion at home, Medicare may not cover this unless considered medically necessary.

Medicare providers can help determine coverage availability and what a prescriber may need to prove the medical necessity.

Read more about Medicare from our dedicated hub.

Doctors may recommend medicated IV infusions for people with UC. These medications include biologics, TNF-alpha blockers, and immunosuppressants.

Each drug has a specific dosage, timings, and side effects. People should discuss these factors with their doctor and check their insurance plans before deciding on treatment.