Key takeaways
- Biologic medications, administered by infusion, can help induce and maintain remission in people with Crohn’s disease by targeting specific proteins that drive inflammation.
- Prior to receiving a Crohn’s infusion, it is important to inform a doctor of all medications a person is taking, understand any necessary dietary precautions, and discuss any concerns they may have.
- While Crohn’s infusions can cause side effects such as allergic reactions or increased susceptibility to infections, people can use them in combination with other therapies to improve effectiveness.
An infusion is a method of delivering medication via an IV line or injection.
During an infusion — sometimes called a drip — a healthcare professional will insert a needle into a person’s vein, then connect up a liquid that will gradually but steadily enter the bloodstream.
For people with Crohn’s disease, infusions often consist of biologic drugs. These drugs can help reduce the risk of flares and severe symptoms, but they can also cause side effects.
This article focuses on the types of Crohn’s infusions and what to expect from this treatment.
Biologics are medications that contain substances that living organisms produce. This includes antibodies or other immune compounds.
These substances can help treat Crohn’s disease by targeting specific proteins or pathways involved in inflammation. As a result, they are more precise than other medications, such as immunosuppressants, which affect the whole body.
Doctors categorize these medications based on the specific proteins they target. Not all biologics are available by infusion.
Below are some examples of these medication types.
Anti-tumor necrosis factor agents
Anti-tumor necrosis factor (anti-TNF) agents block a protein called TNF-alpha. They can help reduce Crohn’s disease symptoms and promote intestinal healing.
Examples of these anti-TNF infusions include:
A doctor will choose an appropriate medication to suit an individual’s needs.
Integrin receptor antagonists
These drug types prevent white blood cells, known as leukocytes, from migrating into the gastrointestinal tract.
Infusions of these medications available for Crohn’s disease include natalizumab (Tysabri) and vedolizumab (Entyvio).
Anti-interleukin-12 and interleukin-23 therapy
These drugs target specific inflammatory compounds known as cytokines.
A doctor may prescribe the medication ustekinumab (Stelara), which is a one-time infusion. The person can then give themselves maintenance injections after the first infusion to keep symptoms at bay.
A 2022 study found that most people using this drug required interval doses every 8 weeks, but some required more or less frequent injections.
A doctor will instruct a person on how to prepare for a Crohn’s infusion.
Usually, at least the first infusion will take place in a hospital. This is so medical professionals can monitor for signs of an allergic reaction.
Depending on the drug, subsequent infusions may happen at a medical facility or at home, depending on a person’s reaction and the method of administration.
Here are some tips to help a person prepare for treatment:
- Ensure that the doctor knows which other medications are in use, including any over-the-counter treatments and supplements.
- Find out whether any dietary precautions are necessary before the treatment.
- List any concerns and talk with the doctor about them in advance.
- Wear comfortable clothes.
- Allow time to rest at home after the infusion, just in case it is necessary.
- Take a book or magazine to pass the time during the treatment.
When visiting a healthcare facility, a person may also wish to take additional precautions to prevent the spread of infections, such as COVID-19. They could ask:
- What type of protection is your facility using to prevent the spread of the virus?
- What should I do if I have symptoms that may be due to COVID-19?
- Do I need to take a test before my appointment?
- If I am isolating at home, how can I arrange my appointments?
Before starting treatment, a person should talk with their doctor about what to expect.
To reduce the risk of allergic reactions, a person may receive premedication, such as acetaminophen (Tylenol) or diphenhydramine (Benadryl).
If the person misses an appointment for any reason, they should contact their doctor to discuss options.
During the treatment
Although the procedure may vary slightly, people can usually expect the following when they have a Crohn’s infusion:
- First, a healthcare professional will start an intravenous (IV) line. This involves inserting a small, thin catheter into a vein, usually in the arm.
- Next, the professional will connect the medication to the IV. The medication is usually in an IV bag or bottle with a tube to connect to the IV in the person’s arm.
- When this is ready, the infusion will begin. This may feel cold, but it should not hurt. Because there is a risk of an allergic reaction, the professional may start the infusion at a slightly lower concentration and increase it over time. A person should alert the healthcare professional about any potential symptoms of an allergic reaction, such as difficulty breathing, a rash, nausea, or a headache.
- When the infusion is complete, health professionals will monitor for any reaction. They may recommend that the person have someone else help them get home.
The time an infusion takes varies by medication. For example, an infusion of vedolizumab takes about 30 minutes, whereas an infusion of ustekinumab can take around 1 hour.
After the infusion
A person will not usually experience immediate positive effects after having a Crohn’s infusion. Some drugs may take a few days to make a difference, while others may take several weeks or months.
How often a person must receive infusions varies by medication.
After the first dose of vedolizumab, a person will need to receive another infusion 2 weeks later, then another 4 weeks later, and every 4 to 8 weeks after that.
However, with ustekinumab, a person will receive a one-time infusion at a hospital or infusion center, followed by injections at home at regular intervals. A medical professional may teach them how to self-inject, where possible.
A doctor will monitor the treatment and determine whether any adjustments to the dosage or schedule are necessary. It is important to follow their instructions.
The cost of biologic treatment can be high. The authors of an older 2017 report put the total cost of treatment with vedolizumab in the first year at $41,320, with subsequent years costing $36,197.
For infliximab, the cost for the first year was $38,782, and for subsequent years, $49,897. These costs were for treatment in a hospital setting.
Insurance companies and Medicare may cover the cost of some biologics for Crohn’s disease. However, a 2025 review found that fewer than 20% of insurance companies accepted biologics as a first-line therapy. They may require a person to try other options first.
Biosimilars may help to reduce the cost of this treatment. These drugs are almost identical to biologics and have similar safety and effectiveness profiles, but they are cheaper.
A person should check their insurance plan before deciding on treatment.
Crohn’s infusions can cause a range of side effects. Many of these are specific to the particular medication the person receives.
When receiving any medication intravenously, it is possible to have an allergic reaction or local reaction at the IV site.
Another risk associated with Crohn’s infusions is increased susceptibility to infections. For this reason, people should always ensure they are up to date on their immunizations before receiving infusions, avoiding any live vaccines that contain microbes.
That said, not all biologics are likely to cause serious immune system suppression. For example, integrin receptor antagonists cause minimal suppression, according to a 2025 review.
Some other risks associated with Crohn’s infusions include:
- injection site reactions, such as pain, bruising, or swelling
- headaches
- reactivation of infections, such as tuberculosis or hepatitis B
- a slightly higher risk of some cancers
- blood disorders or neurological conditions, for TNF-α inhibitors
- worsening of heart failure
There are some drug-specific risks people should also be aware of. For example, receiving the Tysabri infusion increases the risk of progressive multifocal leukoencephalopathy.
This condition occurs in people with the John Cunningham virus, which usually causes no symptoms. As a result, doctors will test people for this virus before beginning Tysabri infusions.
There may also be interactions with other drugs. People should make sure that their doctor knows about all the drugs, supplements, and OTC medications they are taking before starting a new treatment.
A doctor may recommend Crohn’s infusions alongside
For example, a person may take an immunomodulator, which alters the immune system, as well as receive biologic infusions. This is known as combination therapy.
However, there are also greater risks of side effects when using both medications. Some of these risks can be serious.
For example, if a person uses anti-TNF medications and azathioprine (Imuran), they are at slightly greater risk of developing lymphoma.
Some other options a doctor may recommend or prescribe include:
- aminosalicylates, such as balsalazide (Giazo, Colazal), to manage inflammation
- corticosteroids, to reduce inflammation
- a liquid diet, if a doctor recommends bowel rest
- surgery, in some cases
- adjusting the diet
Here are some questions people often ask about Crohn’s infusions.
How long an infusion takes will depend on the individual and the medication, but they often take around 30 minutes to 1 hour.
Monoclonal antibodies are a type of biologic treatment that affects the immune system. They can help people manage inflammatory bowel diseases, such as Crohn’s. Examples include vedolizumab (Entyvio) and ustekinumab (Stelara).
Crohn’s infusions are targeted treatments that can help Crohn’s disease go into long-term remission. However, each drug has its own potential benefits and risks.
A doctor can speak with a person considering infusions about the possible effects, based on their individual medical history. This can help them make the most informed decision when managing their Crohn’s disease.