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
The most common side effect of TNF
antagonists is an allergic reaction to the injection (shot) or infusion
(medicine given in a vein—intravenously, or IV). If you have a
reaction to the shot or infusion, it will happen right away, either during the
infusion or within 1 to 2 hours after the infusion or shot. Your doctor may
give you medicines to prevent or stop the reaction.
Symptoms of a
shot or infusion site reaction include:
- Fever.
- Chills.
- Chest
pain.
- Shortness of breath.
- Itching
(pruritus).
- Headache.
- Nausea.
- Heat and
redness (flushing) in the
face.
- 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 a serious infection (such
as
tuberculosis). If you have had tuberculosis (TB) or
know someone who has had it, tell your doctor. TNF antagonists also affect your
body's ability to fight all infections. So if you get a fever, cold, or the flu
while you are taking one of these medicines, let your doctor know right away.
- An increased risk of blood or nervous system disorders. Call your
doctor 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).
- A possible increased risk of
lymphoma (a type of blood cancer). It is not clear
whether this increase is because of the drug or because people with this
disease may already have a higher risk. There have been reports of a rare kind
of lymphoma, occurring mostly in children and teens taking TNF antagonists,
that often results in death.
- An increased risk of liver injuries.
Call your doctor if your skin starts to look yellow, if you are very tired, or
if you have a fever or dark brown urine.
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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