Examples
Mitoxantrone is not officially approved (labelled or indicated) for MS treatment in Canada. However, it is an approved medication, and some clinics and neurologists are using the medication for people whose MS is rapidly progressing or who have not responded well to other therapies (an unlabelled use).1
How It Works
Mitoxantrone is an immunosuppressant, a type of
medication that reduces the activity of the
immune system. It has been used to treat
leukemia and some advanced prostate cancer. Since
multiple sclerosis (MS) appears to be a disease in
which the immune system attacks the covering of the nerves (myelin sheath)
within the brain and spinal cord, immunosuppressants may slow the progression
of the disease. Immunosuppressants other than mitoxantrone, however, have not
been shown to significantly reduce the progression of MS or the frequency of
relapses.
Mitoxantrone may be injected once every 3 months for up to 3 years.
A higher total dose increases the risk of serious heart damage.
Why It Is Used
Mitoxantrone is not officially approved for MS treatment in Canada, but it is used in both Canada and the United States for treatment of several forms of
advancing MS, including
secondary progressive MS,
progressive relapsing MS, and advanced
relapsing-remitting MS.
Mitoxantrone is one of only two medications that have
been shown to benefit people with secondary progressive MS that is relapsing;
the interferon beta medication Betaseron is the other. Betaseron will likely
remain the first choice for treating secondary progressive MS because it does
not carry the risk of heart damage associated with mitoxantrone. Mitoxantrone may
be tried if you develop severe side effects from Betaseron, cannot take the
medication for some other reason, or continue to have active disease.
How Well It Works
Mitoxantrone reduces the frequency of relapses and helps slow the
development of disability in people with secondary progressive MS that is
relapsing, or advanced relapsing-remitting MS. Some studies have shown that
when mitoxantrone is combined with other drugs such as intravenous
methylprednisolone (IVMP) or Betaseron, the rate of new MS lesions in the brain
has been reduced.2
Side Effects
Use of mitoxantrone may cause serious, even fatal, heart damage in
some people. It also can cause
bone marrow problems. Frequent tests, including a
heart scan, are recommended before each injection of this medication. To reduce
the risk of heart damage associated with the medication, you should receive
only a limited number of doses—the Multiple Sclerosis Society of Canada and the U.S. FDA recommend up to 12 total doses.
Typically, the medication is injected once every 3 months for 2 to 3
years.
Common but less serious side effects of mitoxantrone
include:
- Nausea.
- Hair
loss.
- Increased risk of infections, especially urinary tract
infections.
- Changes in a woman's menstrual cycle.
- Mouth
sores.
- Diarrhea or constipation.
See Drug Reference for a full list of side effects. (Drug Reference
is not available in all systems.)
What To Think About
Due to safety concerns and the limitations on its use, mitoxantrone
is for the most part being used only in specialized MS clinics or centres
staffed by neurologists and other health professionals who specialize in
treating people with MS.
As with interferon beta, people who are taking mitoxantrone need to
have regular blood tests to monitor white and red blood cell counts and liver
function. These are in addition to the regular testing needed to monitor heart
function. Mitoxantrone is not recommended for people who already have heart
disease, liver problems, or certain blood disorders because it may make these
problems worse.
Mitoxantrone should not be used during pregnancy. Women taking
mitoxantrone should use a reliable form of birth control if there is any chance
they could become pregnant. If you become pregnant while you are taking this
medication or are thinking about trying to become pregnant, contact your doctor
immediately.
Complete the
new medication information form (PDF)
(What is a PDF document?)
to help you understand this medication.