Examples
| Generic Name | Brand Name |
|---|
| adalimumab | Humira |
| infliximab | Remicade |
| natalizumab | Tysabri |
How It Works
A tumor necrosis factor (TNF) antagonist is a type of
antibody that inhibits tumor necrosis factor, a
protein that increases inflammation in the body. Infliximab, adalimumab, and
natalizumab block the inflammatory response that happens in
Crohn's disease and
ulcerative colitis. They are given as a shot.
Infliximab and natalizumab are given as a shot in a vein (intravenous, or IV) and adalimumab is given as a shot
under the skin (subcutaneous).
Why It Is Used
Infliximab was first used to treat abnormal connections (fistulas) between the intestines and organs in
moderate to severe Crohn's disease. Now it is used to induce and maintain
remission (a period without symptoms) in people who
have Crohn's disease or ulcerative colitis that has not improved with other
medicines.
Adalimumab and natalizumab are used to induce and maintain
remission in people with Crohn's disease who have not improved with other
medicines and who no longer respond to or cannot tolerate treatment with
infliximab.
How Well It Works
Infliximab can induce remission in people with moderate to severe
Crohn's disease, including the closing of
fistulas. In one study, some people who were treated
with infliximab had symptoms that came back after 3 months. It is now
recommended that people treated with infliximab continue to get the medicine at
regular intervals. This is called maintenance therapy.
In multiple studies, almost 70% of people taking infliximab had
fewer symptoms or had healed fistulas.1
In one study, between 60% and 70% of people with ulcerative colitis
were better 8 weeks after getting infliximab treatment. In another study, twice
as many people got better after receiving infliximab compared to those taking a
placebo.2
Adalimumab has shown promise in treating
Crohn's disease in multiple studies.3 It works like infliximab and may be good for people who are
allergic to infliximab.
Few studies have been done with natalizumab and Crohn's disease.
But the studies that have been done show that natalizumab works well to treat
Crohn's disease.1
The long-term effectiveness of these medicines is still being
studied.
Side Effects
Infliximab and natalizumab are given only in a vein
(intravenously). Adalimumab is given under the skin (subcutaneously). Side
effects include:
- Chest
pain.
- Nausea.
- Fever.
- Chills.
- Itching
(pruritus).
- Facial
flushing.
- Headache.
- Rash.
- Fatigue.
- Dizziness.
Warnings about serious side effects of TNF antagonists have been
issued. The U.S. Food and Drug Administration (FDA) and the drug’s
manufacturers have warned about:
- An increased risk of blood or nervous system
disorders, some potentially fatal. Contact your health professional if you have
symptoms of blood disorders (such as bruising or bleeding) or symptoms of
nervous system problems (such as numbness, weakness, tingling, or vision
problems).
- An increased risk of a serious infection (such as
tuberculosis). If you have had tuberculosis (TB) or know someone who has, tell
your doctor. TNF antagonists also affect your body's ability to fight all
infections, so if you are taking the medicine and get a fever, cold, or flu,
let your doctor know right away.
- An increased risk of liver
injuries, some potentially fatal. Call your doctor if your skin starts to look
yellow, if you have dark brown urine or a fever, or if you are very
tired.
- A possible increased risk of developing
lymphoma (a type of blood cancer). It is not clear if
this increase is because of the drug or because people with Crohn's disease may
already have a higher risk.4 There have been reports
of a rare kind of lymphoma, occurring mostly in children and teens taking TNF
antagonists, that often results in death.
- A possible reaction to
the shot. Some people will have hives, trouble breathing, or low blood pressure
after an infusion of infliximab. Some people can have an allergic reaction to a
shot of adalimumab. Signs of a serious allergic reaction include a skin rash, a
swollen face, or trouble breathing. These reactions most often occur right
away, and your doctor may give you medicines to prevent or stop the
reaction.
In very few cases, natalizumab has caused a serious and
life-threatening disease called PML. Natalizumab is tightly controlled because
of this. If you take natalizumab, you will need to enroll in a program called
the Crohn's Disease–Tysabri Outreach Unified Commitment to Health (CD-TOUCH)
Prescribing Program.
What To Think About
TNF antagonists are more expensive than other medicines used to
treat Crohn's disease.
TNF antagonists are used for Crohn's disease and ulcerative colitis
that has not improved (refractory disease) when treated with corticosteroids,
aminosalicylates, antibiotics, azathioprine, or 6-mercaptopurine.
The use of TNF antagonists during pregnancy is still being studied.
Some of them may be used when other medicines have not worked and the health of
the mother or of the fetus (or both) is at risk. It is not known if TNF
antagonists can pass from the mother to the baby in breast milk. If you have
inflammatory bowel disease and you are pregnant, thinking about becoming
pregnant, or breast-feeding, talk to your doctor about what medicines are safe
for you to use.
Because adalimumab is given as a shot under the skin, you may be
able to do the shots yourself after your doctor has shown you how.
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