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P A R T 2
Chemotherapeutic agents
CHAPTER SUMMARY
■■
A protozoan is a parasitic cellular organism. Its life
cycle includes a parasitic phase inside human tissues
or cells.
■■
Malaria is caused by
Plasmodium
protozoa, which
must go through a cycle in the
Anopheles
mosquito
before being passed to humans by the mosquito bite.
Once inside a human, the protozoa invade red blood
cells.
■■
The characteristic cyclic chills and fever of malaria
occur when red blood cells burst, releasing more
protozoa into the bloodstream.
■■
Malaria is treated with a combination of drugs that
attack the protozoan at various stages in its life cycle.
■■
Amoebiasis is caused by the protozoan
Entamoeba
histolytica
, which invades human intestinal tissue
after being passed to humans through unsanitary
food or water. It is best treated with metronidazole or
tinidazole.
■■
Leishmaniasis, a protozoan-caused disease, can result
in serious lesions in the mucosa, viscera and skin. It is
treated with systemic pentamidine.
■■
Trypanosomiasis, which is caused by infection
with a
Trypanosoma
parasite, may assume two
forms: African sleeping sickness which leads to
inflammation of the CNS, and Chagas disease which
results in serious cardiomyopathy. These diseases can
be treated with systemic pentamidine.
■■
Trichomoniasis is caused by
Trichomonas vaginalis
.
This common cause of vaginitis results in no signs or
symptoms in men but serious vaginal inflammation
in women. It is treated with metronidazole and
tinidazole.
■■
Giardiasis, which is caused by
Giardia lamblia
,
is a very commonly diagnosed intestinal parasite
in Australia. This disease may lead to serious
malnutrition when the pathogen invades intestinal
mucosa. It is treated with metronidazole and
tinidazole.
■■
Pneumocystis carinii
is an endemic protozoan that
does not usually cause illness in humans unless they
become immunosuppressed.
P. carinii
pneumonia
(PCP) is the most common opportunistic infection
seen in AIDS people. It is treated with inhaled
pentamidine and oral atovaquone.
■■
Individuals receiving antiprotozoal agents should be
monitored regularly to detect any serious adverse
effects, including loss of vision, liver toxicity and
so on.
Knowing your strengths and weaknesses helps you to
study more effectively. Take a PrepU Practice Quiz
to find out how you measure up!
Provide teaching regarding drug name, dosage, adverse
effects, precautions and warning signs to report and
hygiene measures to observe.
Evaluation
Evaluate drug effects: resolution of protozoal infection.
Monitor for adverse effects: GI alterations, dizziness,
confusion, CNS changes, vision loss, hepatic function,
superinfections.
Monitor for drug–drug interactions with oral
anticoagulants, alcohol or barbiturates.
Evaluate effectiveness of teaching program.
Evaluate effectiveness of comfort and safety measures.
TEACHING FOR J.C.
You have been prescribed metronidazole to treat your
amoebic infection. This antiprotozoal drug acts to destroy
certain protozoa that have invaded your body. Because it
affects specific phases of the protozoal life cycle, it must
be taken over a period of time to be effective. It is very
important to take all the drug that has been ordered for you.
• This drug frequently causes stomach upset. If it causes
you to have nausea, heartburn or vomiting, take the drug
with meals or a light snack.
• Common effects of this drug include the following:
•
Nausea, vomiting and loss of appetite:
Take the drug with
food and have small, frequent meals.
•
Superinfections of the mouth, skin:
These go away when
the course of the drug has been completed. If they
become uncomfortable, notify your healthcare provider
for an appropriate solution.
•
Dry mouth, strange metallic taste:
Frequent mouth care
and sucking sugarless lozenges may help. This effect will
also go away when the course of the drug is finished.
•
Intolerance to alcohol (nausea, vomiting, flushing, headache
and stomach pain):
Avoid alcoholic beverages or products
containing alcohol while taking this drug.
• Report any of the following to your healthcare provider:
sore throat, fever or chills; skin rash or redness; severe
gastrointestinal upset; and unusual fatigue, clumsiness or
weakness.
• Take the full course of your prescription. Never use this
drug to self-treat any other infection or give it to any other
person.
• Tell any doctor, nurse or other healthcare provider that
you are taking this drug.
• Keep this drug and all medications out of the reach of
children.
