Small Animal Clinical Pharmacology - CYF MEDICAL DISTRIBUTION

CHAPTER 15 CANCER CHEMOTHERAPY
current oncology texts for further advice. Management
of extravasation of specific drugs is also discussed in the
relevant section later in this chapter. Extravasation is
best prevented by:
● adequate patient restraint during drug infusion
● careful attention to correct IV catheter placement.
Vesicant/irritant drugs should be administered
through the side arm of a drip set connected to an
IV catheter with rapidly flowing fluid of
appropriate type
● vigilant monitoring of the animal/injection site
during drug infusion
● prompt discontinuation of infusion if extravasation
is suspected.
Acute tumor lysis syndrome, uncommon in dogs and
very rare in cats, should be distinguished from drug
toxicity. The syndrome is most commonly reported in
patients treated for lymphoma or leukemia and is best
characterized as a metabolic disturbance associated
with hyperuricemia and electrolyte disturbances. Specific
management of this syndrome is detailed in current
oncology texts.
Cytotoxic agents may impair fertility and breeding of
animals undergoing chemotherapy is probably unwise.
Where possible, avoid cytotoxic drug administration
during the proliferative phase of wound healing.
Cytotoxic drugs rarely cause alopecia in cats and dogs
but some coat and hair changes may occur. In cats, loss
of whiskers is a common sequela to chemotherapy.
Certain breeds of dog, particularly poodles and old
English sheepdogs, may lose significant amounts of coat
and some breeds, e.g. golden retrievers may lose the
long hairs from their coat. Hyperpigmentation of the
skin may also occur.
Be aware that, in view of the seriousness of the indications
for use of cytotoxic agents, there are few, if any,
absolute contraindications to their use. Contraindications
noted below for each drug should be viewed as
warnings and the treatment risks and benefits carefully
considered for each patient.
DRUG HANDLING
There are remarkably few data linking health worker
disease with occupational exposure to cytotoxic agents.
However, given that many cytotoxic agents are carcinogenic
with no known risk-free dose, or may cause local
toxicity or allergic problems, consideration of safe work
practices is warranted. For oncology nurses, a strong
link exists between safe work practices and reduced
drug exposure, as indicated by urinary excretion of
cytotoxic agents.
Exposure may be through skin or mucous membrane
absorption, inhalation, ingestion or needle-stick injury.
Exposure may occur during preparation, administration,
spillage or disposal of agents.
Acceptable safe work practices will differ between
different centers depending on local and regional legislative
requirements, the oncology case load of the
clinic and other factors such as availability of cytotoxic
reconstitution services and cytotoxic waste disposal
facilities.
A complete review of safe drug handling is beyond
the scope of this chapter and the reader is encouraged
to consult the references for more detailed advice. Practices
using cytotoxic drugs regularly should establish a
set of local rules and guidelines on the handling, administration
and disposal of these agents.
Common sense dictates the following general
guidelines.
● An area of the practice should be designated as
a cytotoxic drug preparation area. Ideally this
should be a low-traffic, draft-free space. If use of
chemotherapy is significant (daily/weekly) then a
laminar flow biological safety cabinet should be used
or the agents purchased in reconstituted, ready-toadminister
form.
● Do not consume or prepare food or smoke cigarettes
in drug preparation areas.
● Avoid aerosol formation in all phases of drug preparation;
Luer-Lok syringes are recommended to
prevent separation of the syringe from its attachment.
Venting needles may be used to withdraw
solutions from vials.
● Minimum protective clothing requirement for avoiding
direct drug contact during preparation or delivery
is to wear no-powder latex gloves of suitable thickness
for protection against inadvertent contact with
chemotherapy agents. Specialized cytotoxic protective
clothing, including gloves, armsleeves and fulllength
gowns, is available and its use is advisable.
● Tablets formulated with an outer coating covering
the active ingredient are not hazardous to handle
but gloves are recommended for administration of
tablets. The tablets should not be broken.
● Use a designated chemotherapy waste disposal container
for contaminated waste, preferably one suitable
for sharps.
● Ensure that a procedure is in place for managing
spills and biological wastes of hospitalized patients.
● It may be prudent to consider absolving pregnant
women from work with cytotoxic agents.
STABILITY OF INJECTABLE
CYTOTOXIC DRUGS
The duration of stability of an injectable agent after
partial use of the manufacturer’s container is important
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