Apo-Tamox 10540-29-1 Nicotinamide Riboside NR Supplement Nolvadex
Tamoxifen, the generic name of Nolvadex, is the oldest and
most-prescribed SERM. Tamoxifen is approved by the U.S. Food and
Drug Administration (FDA) to treat:
women and men diagnosed with hormone-receptor-positive, early-stage
breast cancer after surgery (or possibly chemotherapy and
radiation) to reduce the risk of the cancer coming back (recurring)
women and men diagnosed with advanced-stage or metastatic
Tamoxifen also is used to:
Tamoxifen won't work on hormone-receptor-negative breast cancer.
Tamoxifen is a pill taken once a day. Most doctors recommend taking
tamoxifen at the same time each day.
You should not take tamoxifen if you are breastfeeding, pregnant,
trying to get pregnant, or if there is any chance that you could be
pregnant. Tamoxifen may cause damage to developing embryos. You
should use an effective non-hormonal type of birth control -- such
as condoms, a diaphragm along with spermicide, or a non-hormonal
I.U.D. – while you are taking tamoxifen and for 2 months afterward.
Ask your doctor which type of non-hormonal birth control would be
best for you.
Benefits of tamoxifen
Since its approval in 1998, tamoxifen has been used to treat
millions of women and men diagnosed with hormone-receptor-positive
breast cancer. While an aromatase inhibitor is the first hormonal
therapy medicine choice for postmenopausal women, tamoxifen is the
first choice for premenopausal women and is still a good choice for
postmenopausal women who can't take an aromatase inhibitor.
reduce the risk of breast cancer coming back by 40% to 50% in
postmenopausal women and by 30% to 50% in premenopausal women
reduce the risk of a new cancer developing in the other breast by
shrink large, hormone-receptor-positive breast cancers before
slow or stop the growth or advanced (metastatic)
hormone-receptor-positive breast cancer in both pre- and
lower breast cancer risk in women who have a higher-than-average
risk of disease but have not been diagnosed
Tamoxifen offers other health benefits that aren't related to
treating cancer. Because it's a SERM, it selectively either blocks
or activates estrogen's action on specific cells. While tamoxifen
blocks estrogen's action on breast cells, it activates estrogen's
action in bone and liver cells. So tamoxifen can:
Some people may not get the full benefit of tamoxifen
The body uses an enzyme called CYP2D6 to convert tamoxifen into its
active form. Two things can interfere with the body’s ability to
make this happen: a flaw in the CYP2D6 enzyme and certain
medications that block the effectiveness of this enzyme.
Abnormal CYP2D6 enzyme: About 10% of people have a CYP2D6 enzyme that doesn’t function as
well as it should. Having an abnormal CYP2D6 enzyme might keep a
person from getting the full benefit of tamoxifen. You may want to
ask your doctor about being tested for this enzyme abnormality if
you are considering taking tamoxifen. Still,CYP2D6 testing is controversial because several large studies found that
an abnormal CYP2D6 enzyme didn’t affect tamoxifen’s effectiveness.
Together, you and your doctor can decide if CYP2D6 testing makes sense for your unique situation.
Medications that can interfere with CYP2D6: There are medications that can block the activity of CYP2D6 to
varying degrees (usually stated as “strong” or “moderate”
inhibitors of CYP2D6). These medications include some of the
antidepressants known as serotonin-specific reuptake inhibitors
(SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs).
There are also other types of commonly prescribed medications, such
as Cardioquin (chemical name: quinidine), Benadryl (chemical name:
diphenhydramine), and Tagamet (chemical name: cimetidine), that can
block CYP2D6. Blocking the activity of CYP2D6 can interfere with the activation of tamoxifen — reducing its
effectiveness as an anti-cancer treatment. Most doctors recommend
that you avoid taking strong and moderate inhibitors of CYP2D6 while you’re on tamoxifen.
If you have already finished tamoxifen and you were taking other
medications at the same time, make an appointment to talk with your
doctor about whether any of your other medications may have
interfered with CYP2D6 and the potential benefit you received from
tamoxifen. Your doctor may recommend no additional therapy or
extended hormonal therapy (with tamoxifen or an aromatase
inhibitor) depending on your risk of recurrence, your overall
medical condition, and your preferences.
If you were taking tamoxifen because you are at high risk but have
never been diagnosed, and you were also taking a CYP2D6 inhibitor,
your doctor may now recommend additional anti-estrogen therapy with
tamoxifen or Evista (chemical name: raloxifene), depending on your
menopausal status. Talk to your doctor about what’s best for your
If you had progression of breast cancer while on both tamoxifen and
a strong or moderate CYP2D6 inhibitor, you can’t assume that
tamoxifen failed to work. Rather, it’s possible that tamoxifen
never had a fair chance at getting the cancer under control because
its action was blocked by the other medicine. Moving forward,
tamoxifen, without a CYP2D6 inhibitor, may still provide
For those taking raloxifene (brand name: Evista)
The CYP2D6 enzyme is not needed to activate raloxifene (brand name:
Evista, a sister medicine to tamoxifen, used to reduce the risk of
developing hormone-receptor-positive breast cancer and treat
osteoporosis in postmenopausal women).
Medicines to avoid while taking tamoxifen
In the list below, the medications under the headings “Strong
Inhibitors” and “Moderate Inhibitors” can inhibit CYP2D6 and
interfere with the effectiveness of tamoxifen. The medications
under the heading “Not Inhibitors” do not block the CYP2D6 enzyme
and will not interfere with tamoxifen treatment.
This list is incomplete and subject to change over time. Use it as
a starting place and ask your doctor if any medications you are
taking or that are recommended to you are compatible with
SSRIs and SNRIs That Are Not Inhibitors