Antibacterials
Antibacterials
are similar to antibiotics but with a difference: originally antibiotics
were derived from moulds and fungi, whereas antibacterials were developed
from chemicals. Early antibacterials like the sulpha-drugs were derived
industrial dyes that was metabolized by the body into sulphanilamide,
the active antibacterial ingredient. Sulpha drugs, introduced in the 1930s,
have proved to be effective against many bacterial infections.
Sulphonamides
followed the original sulpha drugs. Bacterial resistance to sulpha drugs,
like that of resistance to antibiotics, have resulted in doctors switching
over to antibiotics that are more effective and safe. But the days of
the sulphonamide antibacterials are not yet over.
Sulphonamides
reach high concentrations in the urine. They are therefore useful in treating
infections of the urinary tract. They are also used for chlamydia, pneumonia
and for some middle ear infections; sulphacetamide is often included in
topical preparations for skin, eye and other ear infections. Sulphamethoxazole,
in combination with trimethoprim, often in a single large dose (also known
as co-trimoxazole), is used for bladder infections, certain types of bronchitis
and some gastrointestinal infections.
There are
of course a range of antibacterials that are not sulphonamides: those
used against leprosy, TB and malaria; those used against protozoal infections
(like metronidazole, diloxanide furoate). There are others, also known
as antimicrobials, include metronidazole, used for a variety of genital
infections, and some serious infections in the abdomen, pelvic region,
the heart and central nervous system. Nalidixic acid and nitrofurantoin
are effective as antiseptics for the urinary tract, and are used to cure
or prevent recurrent infections.
Antibacterials
work by preventing the growth and multiplication of the organisms, somewhat
similar to antibiotics.
Antibacterials
may take several days to wipe out the bacteria. During this time additional
medication to relieve pain and fever is usually advised. Sulphonamides
in particular can cause loss of appetite, rash, nausea and drowsiness.
Risks and
special precautions of antibacterials include allergic reactions, rashes
and fever. The doctor should be consulted in case a change of antibacterial
is required.
Serious,
but rare risks, with some sulphonamides include formation of crystals
in the kidneys, a risk that can be reduced by drinking adequate amounts
of fluid during prolonged treatment. Sulphonamides may occasionally damage
the liver; they are not usually prescribed for people with liver problems.
Damage to bone marrow is another possibility, leading to lowered production
of white blood cells and increased chances of infection. Doctors therefore
try avoiding use of sulphonamides for long periods. It is advisable to
monitor the liver and blood content, during long-term treatment that may
be absolutely necessary.
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