ANTIGEN
ANTIPSYCHOTIC DRUGS
A
Antifungal preparations are available in
various forms including tablets, injec-
tion, creams, and pessaries. Prolonged
treatment of serious fungal infections
can result in side effects that include
liver or kidney damage.
antigen
A substance that can trigger an
immune response,
resulting in produc-
tion of an
antibody
as part of the body's
defence against infection and disease.
Many antigens are foreign proteins (not
found naturally in the body) such as
parts of microorganisms and toxins or
tissues from another person that have
been used in organ transplants. Some-
times, harmless substances (pollen, for
example)
are
misidentified
by
the
immune system as potentially harmful
antigens, which results in an allergic
response (see
allergy).
antihistamine drugs
A group of drugs
that block the effects of
histamine,
a
chemical released in allergic reactions
(see
allergy).
Antihistamines are used
to treat rashes such as
urticaria
and to
relieve sneezing and a runny nose in
allergic
rhinitis.
They are also some-
times included in
cough rem edies
and
cold rem edies
and are used as
antiem-
etic drugs.
Antihistamines are usually
taken by mouth but may be given by
injection for
anaphylactic shock.
Many
antihistamines cause drowsiness, but
newer drugs have little sedative effect.
Other possible side effects include loss
of appetite, nausea, dry mouth, blurred
vision, and difficulty in passing urine.
antihypertensive drugs
A group of
drugs used in the treatment of
hyper-
tension
to prevent complications such
as
stroke, myocardial infarction, heart
failure,
and kidney damage. There are
several types, including
angiotensin II
antagonists, beta-blocker drugs, ACE
inhibitor drugs
,
calcium channel block-
ers,
alpha-blocker drugs,
vasodilator
drugs,
and
diuretic drugs.
Side effects
depend on the type of antihypertensive
drugs used, but all can cause dizziness
if the blood pressure falls excessively.
anti-inflammatory drugs
Drugs that
reduce
inflammation
. The main groups
of these drugs are
nonsteroidal anti-
inflammatory drugs
and
corticosteroid
drugs. (See
also
analgesic drugs.)
antimalarial drugs
Drugs used to treat
malaria
. One antimalarial drug,
chloro-
quine,
is also used to treat arthritis.
antioxidant
A type of chemical that
neutralizes potentially damaging oxidiz-
ing molecules known as
free radicals
.
Some antioxidants occur naturally in
the body; others (vitamin C, vitamin E,
and beta-carotene, for example) are
obtained through food intake or from
dietary supplements.
antiperspirant
A substance applied to
the skin in the form of a lotion, cream,
or spray to reduce sweating. High con-
centrations are sometimes used to treat
hyperhidrosis
(abnormally heavy sweat-
ing). Antiperspirants may cause skin
irritation, particularly if they are used
on broken skin. (See also
deodorants.)
antiplatelet drugs
Drugs that reduce
the tendency of
platelets
to stick to-
gether to form blood clots when blood
flow in the arteries is disrupted. This
action reduces the risk of
thrombo-
embolism
, which can cause potentially
fatal disorders such as a
myocardial
infarction
or
stroke
.
Aspirin
and dipyri-
damole are commonly used antiplatelet
drugs. Others, such as ticlopidine, are
used specifically to protect against clots
forming in the
coronary arteries
of peo-
ple with
angina
.
antipruritic drugs
Drugs that are used
to relieve persistent itching (
pruritus
).
Antipruritics may be applied as creams
and
emollients
and may contain
corti-
costeroid drugs, antihistamine drugs,
or
local anaesthetics
. Oral antihistamines
may also be used to relieve itching.
antipsychotic drugs
A group of drugs
used to treat
psychoses
(mental disor-
ders involving loss of contact with
reality), particularly
schizophrenia
and
mania
in bipolar disorder (see
manic-
depressive illness
). Antipsychotic drugs
may also be used to sedate people who
have other mental disorders (such as
dementia
) and who are very agitated or
aggressive. Antipsychotics include
phe-
nothiazine drugs,
butyrophenones, such
as
haloperidol,
and several new drugs
including risperidone, which is used to
treat the symptoms of mania.
Antipsychotics can cause drowsiness,
lethargy,
dyskinesia
, and
parkinsonism
.
42
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