212
P A R T 2
Chemotherapeutic agents
■■
Mitotic inhibitors kill cells during the M phase and
are used to treat a variety of cancers.
■■
These drugs are usually given intravenously.
Extravasation could be a serious problem.
■■
Bone marrow suppression, alopecia and toxic GI
effects are common adverse effects of the mitotic
inhibitors.
HORMONES AND HORMONE
MODULATORS
Some cancers, particularly those involving the breast
tissue, ovaries, uterus, prostate and testes, are sensitive
KEY POINTS
to oestrogen stimulation. Oestrogen-receptor sites on
the tumour react with circulating oestrogen, and this
reaction stimulates the tumour cells to grow and divide.
Several antineoplastic agents are used to block or inter
fere with these receptor sites to prevent growth of the
cancer and in some situations to actually cause cell
death. Some hormones are used to block the release of
gonadotropic hormones in breast or prostate cancer if
the tumours are responsive to gonadotropic hormones.
Others may block androgen-receptor sites directly and
are useful in the treatment of advanced prostate cancers.
Hormones and hormone modulators include abiraterone
(
Zytiga
), anastrozole (
Arianna, Arimidex
), bicalutamide
(
Calutex, Cosudex
), cabazitaxel (
Jevtana
), degare
lix (
Firmagon
), exemestane (
Aromasin
), flutamide
(
Eulexin, Flutamin
), fulvestrant (
Faslodex
), goserelin
(
Zoladex
), letrozole (
Femara
), megestrol (
Megace
), nilu
tamide (
Anandron
), tamoxifen (
Nolvadex
,
Tamosin
),
toremifene (
Fareston
) and triptorelin (
Diphereline
) (see
Table 14.5).
Therapeutic actions and indications
The hormones and hormone modulators used as anti
neoplastics are receptor-site specific or hormone specific
to block the stimulation of growing cancer cells that
are sensitive to the presence of that hormone (see
Figure 14.4). These drugs are indicated for the treat
ment of breast cancer in postmenopausal women or in
other women without ovarian function. Some drugs
are indicated for the treatment of prostatic cancers
that are sensitive to hormone manipulation. Table 14.5
shows usual indications for each of the hormones and
hormone modulators.
Pharmacokinetics
These drugs are readily absorbed from the GI tract,
metabolised in the liver and excreted in the urine.
Caution must be used with any individual who has
hepatic or renal impairment. These drugs cross the
placenta and enter into breast milk.
Contraindications and cautions
These drugs are contraindicated during pregnancy
and breastfeeding
because of toxic effects on the fetus
and neonate
. Hypercalcaemia is a contraindication
to the use of toremifene,
which is known to increase
calcium levels.
Use caution when giving hormones and
hormone modulators to anyone with a known allergy
to any of these drugs. Care is necessary in people with
bone marrow suppression,
which is often the index for
redosing and dosing levels
, and in those with renal or
hepatic dysfunction,
which could interfere with the
metabolism or excretion of these drugs and often indi-
cates a need to change the dose.
scarf or hat
is important for maintaining body
temperature
. If alopecia is an anticipated effect
of drug therapy, advise the person to obtain a
wig or head covering before the condition occurs
to promote self-esteem and positive body image
.
■
■
Provide the following teaching:
–– Follow the appropriate dosage regimen, including
dates to return for further doses.
–– Maintain nutrition if GI effects are severe.
–– Cover the head at extremes of temperature if
alopecia is anticipated.
–– Plan for appropriate rest periods because fatigue
and weakness are common effects of the drugs.
–– Avoid situations that might lead to infection,
including crowded areas, sick people and working
in the soil.
–– Use safety measures such as avoiding driving
or using dangerous equipment, due to possible
dizziness, headache and drowsiness.
–– Consult with a healthcare provider, as
appropriate, due to the possibility of impaired
fertility.
–– Use barrier contraceptives to reduce the risk of
pregnancy during therapy.
Evaluation
■
■
Monitor response to the drug (alleviation of cancer
being treated and palliation of signs and symptoms
of cancer).
■
■
Monitor for adverse effects (bone marrow
suppression, GI toxicity, neurotoxicity, alopecia,
renal or hepatic dysfunction, and local reactions at
the injection site).
■
■
Evaluate the effectiveness of the teaching plan
(person can name the drug, dosage, possible
adverse effects to watch for and specific measures
to help avoid adverse effects).
