2. Drugs
are complex molecules containing carbon, hydrogen with some
heteroatom like oxygen, nitrogen, sulfur.
On the basis of their action of different microorganism and mode of
action, drugs can be various types.
Some common classes of drugs are as follows.
Antipyretics: These drugs used to reduce fever.
Analgesics: They are painkiller which used to reduce pain
Antimalarial drugs: these drugs use to treat malaria
Antibiotics: They inhibited the germ growth which caused disease
Antiseptics: They used to prevention of germ growth near burns,
cuts and wounds
3.
4.
5. HISTORICAL PERSPECTIVES
• The discovery of the first antibiotic was an
accident.
– Alexander Fleming accidentally contaminated a
plate with a fungus.
– He observed a clearly defined region of no
bacterial growth where the fungi had contaminated
the plate.
– The area around the fungus was eventually
referred to as a zone of inhibition.
6. …HISTORICAL PERSPECTIVES
• It is estimated that over 80 million
prescriptions are written in America each year.
• 12,500 tons of antibiotics are produced
annually.
– 25-50 % is fed to livestock to increase the rate of
weight gain.
• From 1900 to 1980, mortality from infectious
diseases dropped from 797 per 100,000
persons to 36 per 100,000 persons.
7. …HISTORICAL PERSPECTIVES
• No major discoveries of natural antibiotic
substances have occurred for several years.
– Efforts have now shifted to modifying existing
antibiotics.
– Searching in new places for potential antibiotics has
also gained in prominence.
• Many antibiotics are produced by microorganisms
as part of their survival mechanism.
– They keep other organisms away.
– They protect the supply of nutrients and oxygen.
8. Penicillin - the first antibiotic
• Penicillin was the first antibiotic to be
discovered.
• It was discovered in 1928 by Alexander
Fleming, a Scottish scientist working in St
Mary's Hospital London.
• Fleming discovered that mould from a
Penicillium fungus had antibacterial
properties. The antibiotic was named
penicillin after the fungus.
8
9. Penicillin - the first antibiotic
• Fleming could not extract enough penicillin from the mould to use for the
treatment of patients
• In 1938, Howard Florey (an Australian microbiologist), Ernst Chain (a
German chemist) and others at Oxford University pioneered the production
of penicillin for human treatment. But they had to depend on
pharmaceutical companies in the United States to produce penicillin on a
large scale.
• Penicillin was first released for widespread use in the early 1940’s and it
saved many lives during World War II.
9 Howard Florey Ernst Chain
