Anti-infective
Drugs books
Anti-infective
drugs are classified as antibacterials, antivirals,
or antifungals depending on the type of microorganism
they combat. Anti-infective drugs interfere selectively
with the functioning of a microorganism while leaving
the human host unharmed.
Antibacterial drugs, or antibiotics-sulfa drugs, penicillins,
cephalosporins, and many others-either kill bacteria
directly or prevent them from multiplying so that the
body's immune system can destroy invading bacteria.
Antibacterial drugs act by interfering with some specific
characteristics of bacteria. For example, they may destroy
bacterial cell walls or interfere with the synthesis
of bacterial proteins or deoxyribonucleic acid (DNA)-the
chemical that carries the genetic material of an organism.
Antibiotics often cure an infection completely. However,
bacteria can spontaneously mutate, producing strains
that are resistant to existing antibiotics.
Antiviral drugs interfere with the life cycle of a virus
by preventing its penetration into a host cell or by
blocking the synthesis of new viruses. Antiviral drugs
may cure, but often only suppress, viral infections;
and flare-ups of an infection can occur after symptom-free
periods. With some viruses, such as human immunodeficiency
virus (HIV), which causes acquired immunodeficiency
syndrome (AIDS), antiviral drugs can only prolong life,
not cure the disease.
Vaccines are used as antiviral drugs against diseases
such like mumps, measles, smallpox, poliomyelitis, and
influenza. Vaccines are made from either live, weakened
viruses or killed viruses, both of which are designed
to stimulate the immune system to produce antibodies,
proteins that attack foreign substances. These antibodies
protect the body from future infections by viruses of
the same type.
Antifungal drugs selectively destroy fungal cells by
altering cell walls. The cells' contents leak out and
the cells die. Antifungal drugs can cure, or may only
suppress, a fungal infection.
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