BENZYLPENICILLIN
BETA-BLOCKER DRUGS
B
benzylpenicillin
A type of
penicillin drug
that is given by injection.
bereavement
The emotional reaction
following the death of a loved relative
or friend. The expression of grief is indi-
vidual to each person, but there are
recognized stages of bereavement, each
characterized by a particular attitude. In
the first stage, which may last from 3 days
to 3 months, there is numbness and an
unwillingness to recognize the death.
Hallucinations, in which the dead person
is seen, are a common experience. Once
the numbness wears off, the person may
be overwhelmed by feelings of anxiety,
anger, and despair that can develop into
a depressive illness (see
depression
).
Insomnia, malaise, agitation, and tear-
fulness are also common. Gradually,
but usually within 2 years, the bereaved
person adjusts to the loss.
Family and friends can often provide
support. Outside help may be required
and may be given by a social worker,
health visitor, member of the clergy, or
self-help group. For some people, when
depression, apathy, and lethargy imp-
ede any chance of recovery, specialized
counselling
or
psychotherapy
is neces-
sary. (See also
stillbirth.)
beriberi
A nutritional disorder result-
ing from a lack of
thiamine
(vitamin B
1
)
in the diet. Without thiamine, the brain,
nerves,
and muscles
(including the
heart muscle) are unable to function
properly. In developed countries, the ill-
ness is seen only in people who are
starving or on an extremely restricted
diet, such as alcoholics. There are 2
forms of the illness. In dry beriberi, thia-
mine
deficiency
mainly
affects
the
nerves and skeletal muscles. Symptoms
include numbness, a burning sensation
in the legs, and muscle wasting. In sev-
ere cases, the patient becomes virtually
paralysed, emaciated, and bedridden. In
wet beriberi, the main problem is
heart
failure
, which leads to
oedem a
(swelling
caused by fluid accumulation) in the
legs, and sometimes also in the trunk
and face. Other symptoms of wet beri-
beri include poor appetite, rapid pulse,
and breathlessness.
Beriberi
is
treated with
thiamine,
given orally or by injection.
berry aneurysm
An abnormal swelling
that occurs at the junction of
arteries
supplying the brain. Berry aneurysms,
which are usually due to a
congenital
weakness, can sometimes rupture, re-
sulting in a
subarachnoid haem orrhage.
(See also
aneurysm.)
berylliosis
An occupational disease that
is caused by the inhalation of dust or
fumes containing beryllium, a metallic
element which is used in high-technol-
ogy industries, such as nuclear energy,
electronics, and aerospace. Short expo-
sure to high concentrations of beryllium
may lead to an episode of severe
pneu-
monitis
. Exposure over a number of years
to smaller concentrations may lead to
permanent damage to lungs and liver.
Treatment with
corticosteroid drugs
can
reduce damage to the lungs. In most
cases, the introduction of safe working
practices prevents exposure to danger-
ous levels of berylliosis.
beta-blocker drugs
A group of drugs,
also known as beta-adrenergic blocking
agents, prescribed principally to treat
heart and circulatory disorders such as
angina
and
hypertension
. Beta-blockers
block the effects of the
sympathetic ner-
vous system
, which releases
adrenaline
(epinephrine) and
noradrenaline
(nor-
epinephrine) at nerve endings that are
known as beta receptors.
There are 2 types of beta receptor:
beta 1 and beta 2. Beta 1 receptors are
present in the heart and blood vessels,
and beta 2 in the lungs. Some beta-
blockers (such as acebutolol, atenolol,
and metoprolol) are termed cardio-
selective and, because they act mostly
on beta 1 receptors, are used mainly to
treat heart disease such as angina,
hypertension
, and cardiac
arrhythmia
.
The drugs are sometimes given after a
myocardial infarction
(heart attack) to
reduce the likelihood of further damage
to the heart muscle.
Other types of beta-blocker, such as
oxprenolol, propranolol, and timolol,
may be given to prevent
migraine
at-
tacks by acting on blood vessels in the
head; reduce the physical symptoms of
anxiety
; or control the symptoms of
thy-
rotoxicosis
. Beta-blocker drugs such as
timolol are sometimes given in the
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