AMOXICILLIN
A
amoxicillin
A
penicillin drug
commonly used to treat
a variety of infections, including
cystitis,
bronchitis,
and ear and skin infections.
Allergy to it causes a blotchy rash and,
rarely, fever, swollen mouth and tongue,
itching, and breathing difficulty.
Amoxil
A brand name for the antibiotic drug
amoxicillin.
amoxycillin
See
amoxicillin.
amphetamine drugs
COMMON DRUGS
• Dexamfetamine
A group of
stimulant drugs
used mainly
in the treatment of
narcolepsy
(a rare
disorder that is characterized by exces-
sive sleepiness).
HOW THEY WORK
Amphetamine drugs stimulate secretion
of
neurotransmitters
(chemicals released
by nerve endings), such as
noradrenaline
(norepinephrine), which increase nerve
activity in the brain and make a person
wakeful and alert.
SIDE EFFECTS
In high doses, amphetamines can cause
tremor, sweating, anxiety, and sleeping
problems. Delusions, hallucinations, high
blood pressure), and seizures may also
occur. Prolonged use may produce
toler-
ance
and
drug dependence
.
ABUSE
Amphetamines are often abused for
their stimulant effect and, for this rea-
son, they are
controlled drugs
.
amphotericin
An antifungal drug used to treat
can-
didiasis
of the mouth or intestine. The
drug is taken as tablets but is also given
by intravenous infusion to treat life-
threatening systemic (generalized) fungal
infections such as
cryptococcosis
and
histoplasmosis
.
Side effects, which include vomiting,
fever, headache, and, rarely, seizures,
may occur with intravenous infusion.
ampicillin
A
penicillin drug
commonly used to treat
cystitis,
bronchitis,
and ear infections.
Diarrhoea is a common adverse effect.
Some people are allergic to ampicillin
and suffer from rash, fever, swelling of
the mouth and tongue, itching, and
breathing difficulty.
ampoule
A small glass or plastic vessel that can be
hermetically sealed to hold liquid sub-
stances,
in
a
sterile
condition,
for
injection.
Each ampoule usually contains
a single dose of a drug.
ampulla
An enlarged, flask-shaped area at the
end of a tubular structure or canal.
There are several ampullae in the body,
including those at the end of each
fallopian tube, on each of the three
semicircular canals of the inner ear, and
at the opening of the bile duct leading
into the intestine.
amputation
The surgical removal of part or all of a
limb. Amputation may be needed if the
blood supply to the limb has been per-
manently lost. It may also be necessary
in some instances of cancer. The oper-
ation is now quite rarely performed.
WHY IT IS DONE
Amputation is necessary if
peripheral
vascular disease,
as a result of
atheroscler-
osis
or
diabetes mellitus,
has destroyed the
blood supply to a limb. If the blood
supply cannot be restored, amputation
is carried out to prevent the develop-
ment of
gangrene
(tissue death).
Amputation may also occasionally be
performed to prevent the spread of a
bone cancer
or malignant melanoma
(see
melanoma, malignant),
a type of
skin cancer. If a limb has been irrepara-
bly damaged in an accident, a decision
may also be taken to amputate.
HOW IT IS DONE
During the operation, skin and muscle
are cut below the level at which the
bone is to be severed to create flaps that
will later provide a fleshy stump. The
blood vessels are tied off, the bone is
sawn through, the area is washed with
saline (salt solution), and the flaps of
skin and muscle are stitched over the
sawn end of bone to form a smooth and
rounded stump.
If a prosthesis (see
limb, artificial
) is to
be fitted, the surgeon tries to ensure
that nerves are severed well above the
stump in order to reduce the risk of
pressure pain. In an amputation at the
ankle (Syme’s amputation), the tough
skin of the heel pad is retained to cover
the stump, reducing the need for a
prosthetic foot.
RECOVERY AND OUTLOOK
The stump is usually swollen for about
six weeks after the operation. For some
time after amputation, there may also be
an unpleasant sensation that the limb is
still
present.
This
phenomenon
is
known as “phantom limb”. A prosthesis
will usually be fitted, if necessary, once
the stump has healed and the swelling
has gone down.
amputation, congenital
The separation of a body part (usually a
limb, finger, or toe) from the rest of the
body, as a result of the blood supply to
the part being blocked, in the uterus, by
a band of
amnion
(fetal membrane). At
birth, the affected part may be either
completely separated, or it may show
the marks of the “amniotic band”. (See
also
limb defects
.)
amputation, traumatic
Loss of a finger, toe, or limb through
injury (See also
microsurgery.)
amylase
An
enzyme
that is found in
saliva
and
pancreatic
secretions
(see
pancreas).
Amylase
helps
the
body
to
digest
dietary starch, breaking it down into
smaller components, such as the sugars
glucose
and maltose.
Amsler chart
A diagnostic tool used by ophthalm-
ologists to detect changes in the retina,
particularly those changes that indicate
macular degeneration.
A typical Amsler
chart consists of a grid of black lines on
a white background. In an individual
with retinal changes, the lines may
appear distorted.
amyl nitrite
A
nitrate drug
that was once prescribed
to relieve
angina pectoris
(chest pain as a
result of impaired blood supply to the
heart muscle). Because it frequently
causes adverse effects, the drug has now
been superseded by other drugs such as
glyceryl trinitrate
and
isosorbide
. Amyl
nitrite is sometimes abused for its effect
of intensifying pleasure during orgasm.
amyloidosis
An uncommon disease in which a sub-
stance
called amyloid,
composed of
fibrous protein, accumulates in tissues
and organs, including the liver, kidneys,
tongue, spleen, and heart.
CAUSES
Amyloidosis may occur for no known
reason, in which case it is known as
primary amyloidosis; more commonly,
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