Most important fact about this drug
Be certain to remember that in the treatment of psoriasis
and rheumatoid arthritis, methotrexate is taken once a week,
not once a day. Accidentally taking the recommended weekly
dosage on a daily basis can lead to fatal overdosage. Be sure
to read the patient instructions that come with the package.
How Is It Used?
Take methotrexate exactly as prescribed,
and promptly report to your doctor any new symptoms that may
develop.
Methotrexate is given at a higher dosage for cancer than for
psoriasis or rheumatoid arthritis. After high-dose methotrexate
treatment, a drug called leucovorin may be given to limit
the toxic effects.
Are
There Possible Side Effects?
Side effects cannot be anticipated. If
any develop or change in intensity, inform your doctor as
soon as possible. Only your doctor can determine whether it
is safe for you to continue taking methotrexate.
- More common side effects may include:
Abdominal pain and upset, chills and fever, decreased resistance
to infection, dizziness, fatigue, general feeling of illness,
mouth ulcers, nausea
- Less common side effects may include:
Abortion, acne, anemia, birth defects, black or tarry stool,
boils, bruises, changes in skin coloration, convulsions,
diarrhea, drowsiness, eye or vision problems, fatigue, hair
loss, headaches, hives, inability to speak, infection of
hair follicles, infertility, inflammation of the gums or
mouth, intestinal inflammation, kidney failure, loss of
appetite, lung disease, menstrual problems, partial or complete
paralysis, rash or itching, red patches on skin, sensitivity
to light, skin peeling or flaking, sore throat, stomach
and intestinal ulcers and bleeding, stomach pain, vaginal
discharge, vomiting, vomiting blood
- Rare side effects may include:
Diabetes, impotence, infection, joint pain, loss of sexual
desire, muscular pain, osteoporosis, ringing in the ears,
severe allergic reaction, shortness of breath, sleepiness,
sudden death, sweating
If you are taking methotrexate
for psoriasis, you may also experience hair loss and/or sun
sensitivity, and your patches of psoriasis may give a burning
sensation.
Methotrexate can sometimes cause serious lung damage that
makes it necessary to limit the treatment. If you experience
a dry cough, fever, or breathing difficulties while taking
methotrexate, be sure to tell your doctor right away.
During and immediately after treatment with methotrexate,
fertility may be impaired. Men may have an abnormally low
sperm count; women may have menstrual irregularities.
People on high doses of methotrexate may develop a brain condition
signaled by confusion, partial paralysis, seizures, or coma.
Why should
this drug not be prescribed?
Do not take this medication if you are
sensitive to it or it has given you an allergic reaction.
Do not take this medication if you are pregnant.
Methotrexate treatment is not suitable for you if you suffer
from psoriasis or rheumatoid arthritis and also have one of
the following conditions:
- Abnormal blood cell count
- Alcoholic liver disease or other chronic liver disease
- Alcoholism
- Anemia
- Immune-system deficiency
Special warnings
about this medication
Before you start taking methotrexate, your doctor will
do a chest X-ray plus blood tests to determine your blood
cell counts, liver enzyme levels, and the efficiency of your
kidney function. While you are taking methotrexate, the blood
tests will be repeated at regular intervals; if you develop
a cough or chest pain, the chest X-ray will be repeated.
If you are being treated for psoriasis or rheumatoid arthritis,
your doctor will test your liver function at regular intervals.
You should avoid alcoholic beverages while taking this drug.
You may develop an opportunistic infection--one that takes
advantage of your altered body chemistry--while you are taking
methotrexate. Before receiving an immunization or vaccination,
be sure to inform health care workers that you are taking
this drug.
Older or physically debilitated people are particularly vulnerable
to toxic effects from methotrexate. Your doctor will prescribe
methotrexate with great caution if you have any of the following:
- Active infection
- Liver disease
- Peptic ulcer
- Ulcerative colitis
What
About Interactions With Other Drugs?
If you are being given methotrexate for
the treatment of cancer or psoriasis, you should not take
aspirin or other nonsteroidal painkillers such as Advil or
Naprosyn; this combination could increase the toxic effects
of methotrexate. If you are taking methotrexate for rheumatoid
arthritis, you may be able to continue taking aspirin or a
nonsteroidal painkiller, but your doctor should monitor you
carefully.
Other drugs that may increase the toxic effects of methotrexate
include:
- Cisplatin (Platinol)
- Penicillins
- Phenylbutazone
- Phenytoin (Dilantin)
- Probenecid
- Retinoid drugs such as Retin-A and Renova
- Sulfa drugs such as Bactrim and Gantrisin
Sulfa drugs may increase
methotrexate's toxic effect on the bone marrow, where new
blood cells are made.
Certain antibiotics, including tetracycline (Sumycin) and
chloramphenicol (Chloromycetin), may reduce the effectiveness
of methotrexate. This is also true of vitamin preparations
that contain folic acid.
In addition, methotrexate can alter the effect of theophylline
(Quibron, Theo-Dur).
Special
information if you are pregnant or breastfeeding
A woman should not start methotrexate therapy until the doctor
is sure she is not pregnant. Because methotrexate causes birth
defects and miscarriages, it must not be taken during pregnancy
by women with psoriasis or rheumatoid arthritis. It should
be taken by women being treated for cancer only if the potential
benefit outweighs the risk to the developing baby. In fact,
a couple should avoid pregnancy if either the man or the woman
is taking methotrexate. After the end of methotrexate treatment,
a man should wait at least 3 months, and a woman should wait
for the completion of at least one menstrual cycle, before
attempting to conceive a child.
Methotrexate should not be taken by a woman who is breastfeeding;
it does pass into breast milk and may harm a nursing baby.
Recommended
dosage
Treatment with methotrexate is highly individualized. Your
doctor will carefully tailor your dosage of methotrexate in
order to avoid serious side effects and possible under- or
overdosing.
In case
of emergency/overdose
Taken in excess, methotrexate can cause serious and even fatal
damage to the liver, kidneys, bone marrow, lungs, or other
parts of the body. Symptoms of overdosage may include lung
or breathing problems, mouth ulcers, or diarrhea. Initially,
however, serious damage caused by methotrexate may be apparent
only in the results of blood tests. For this reason, careful,
regular monitoring by your doctor is necessary. If for any
reason you suspect symptoms of an overdose of this drug, seek
medical attention immediately.
What
If I Miss A Dose?
Skip it and go back to your regular schedule. Do not take
2 doses at once.
How Should It Be
Stored?
Store at room temperature, away from light.
NOTE: The above
information is intended to supplement, not substitute for,
the expertise and judgment of your physician, pharmacist,
or other healthcare professional. It should not be construed
to indicate that the use of the product is safe, appropriate,
or effective for you. Consult your healthcare professional
before taking the product. |
