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Wednesday, 17 June 2009

Antibiotics and Their Types, Uses and Side Effects
An antibiotic is a drug that kills or slows the growth of bacteria. Antibiotics are one class of antimicrobials, a larger group which also includes anti-viral, anti-fungal, and anti-parasitic drugs. Antibiotics are chemicals produced by or derived from microorganisms (i.e. bugs or germs such as bacteria and fungi). The first antibiotic was discovered by Alexander Fleming in 1928 in a significant breakthrough for medical science.
Antibiotics are among the most frequently prescribed medications in modern medicine.
Some antibiotics are 'bactericidal', meaning that they work by killing bacteria. Other antibiotics are 'bacteriostatic', meaning that they work by stopping bacteria multiplying.
Each different type of antibiotic affects different bacteria in different ways. For example, an antibiotic might inhibit a bacterium's ability to turn glucose into energy, or its ability to construct its cell wall. When this happens, the bacterium dies instead of reproducing.
Some antibiotics can be used to treat a wide range of infections and are known as 'broad-spectrum' antibiotics. Others are only effective against a few types of bacteria and are called 'narrow-spectrum' antibiotics.
Side effects of antibiotics
Antibiotics can literally save lives and are effective in treating illnesses caused by bacterial infections. However, like all drugs, they have the potential to cause unwanted side effects. Many of these side effects are not dangerous, although they can make life miserable while the drug is being taken.
In general, antibiotics rarely cause serious side effects. The most common side effects from antibiotics are diarrhea, nausea, vomiting. Fungal infections of the mouth, digestive tract and vagina can also occur with antibiotics because they destroy the protective 'good' bacteria in the body (which help prevent overgrowth of any one organism), as well as the 'bad' ones, responsible for the infection being treated.
Some people are allergic to antibiotics, particularly penicillins. Allergic reactions cause swelling of the face, itching and a skin rash and, in severe cases, breathing difficulties. Allergic reactions require prompt treatment.
Types of antibiotics
There are many different kinds of antibiotics. The type of antibiotics you take depends on the type of infection you have and what kind of antibiotics are known to be effective.
The main classes of antibiotics:
Aminoglycosides
Cephalosporins
Fluoroquinolones
Macrolides
Penicillins
Tetracyclines
Macrolides
There are a couple of new relatives of erythromycin (azithromycin and clarithromycin) that work the same way, but kill more bugs and have slightly fewer side effects. The erythromycin-like antibiotics are also known as macrolides. Macrolides belong to the polyketide class of natural products. Macrolide antibiotics are used to treat respiratory tract infections, genital, gastrointestinal tract, soft tissue infections caused by susceptible strains of specific bacteria.
Macrolides bind with ribosomes from susceptible bacteria to prevent protein production. This action is mainly bacteriostatic, but can also be bactericidal in high concentrations.
Macrolides cause very little allergy problems compared to the penicillins and cephalosporins, the biggest concern with these medicines is that they can irritate the stomach.
The most commonly-prescribed macrolides:
erythromycin
clarithromycin
azithromycin
roxithromycin
Aminoglycosides
Aminoglycoside antibiotics are used to treat infections caused by gram-negative bacteria. Aminoglycosides may be used along with penicillins or cephalosporins to give a two-pronged attack on the bacteria. Aminoglycosides work quite well, but bacteria can become resistant to them. Since aminoglycosides are broken down easily in the stomach, they can't be given by mouth and must be injected. When injected, their side effects include possible damage to the ears and to the kidneys. This can be minimized by checking the amount of the drug in the blood and adjusting the dose so that there is enough drug to kill bacteria but not too much of it. Generally, aminoglycosides are given for short time periods.
The aminoglycosides are drugs which stop bacteria from making proteins. This effect is bactericidal.
The most commonly-prescribed aminoglycosides:
amikacin
gentamicin
kanamycin
neomycin
streptomycin
tobramycin
Cephalosporins
Cephalosporins are grouped into "generations" by their antimicrobial properties. Cephalosporins are categorized chronically, and are therefore divided into first, second, and third generations. Currently, three generations of cephalosporins are recognized and a fourth has been proposed. Each newer generation of cephalosporins has greater gram negative antimicrobial properties than the preceding generation. The later-generation cephalosporins have greater effect against resistant bacteria.
Cephalosporins are used to treat pneumonia, strep throat, staph infections, tonsillitis, bronchitis, otitis media, various types of skin infections, gonorrhea. Cephalosporin antibiotics are also commonly used for surgical prophylaxis. Cephalosporins are closely related to the penicillins.
Cephalosporins have a bacteriocidal effect by inhibiting the synthesis of the bacteria cell wall.
The most commonly-prescribed cephalosporins:
First generation
cephazolin
cefadroxil
cephalexin
cephradine

Second generation

cefaclor
cefuroxime
cefprozil
loracarbef

Third generation

cefotaxime
cefixime
cefpodoxime
ceftazidime
cefdinir

Fourth generation

cefepime
cefpirome

Fluoroquinolones
Fluoroquinolones are known as broad-spectrum antibiotics, meaning they are effective against many bacteria. Fluoroquinolones are used to treat most common urinary tract infections, skin infections, and respiratory infections (such as sinusitis, pneumonia, bronchitis). Common side effects of fluoroquinolones include mainly the digestive system: mild stomach pain or upset, nausea, vomiting, and diarrhea. These are usually mild and go away over time. Fluoroquinolones should not be given during pregnancy.
Fluoroquinolones inhibit bacteria by interfering with their ability to make DNA. This activity makes it difficult for bacteria to multiply. This effect is bacteriocidal.
The most commonly-prescribed fluoroquinolones:
ciprofloxacin
gatifloxacin
gemifloxacin
levofloxacin
moxifloxacin
norfloxacin
ofloxacin
trovafloxacin
Penicillins
Penicillin was the first antibiotic discovered by Alexander Fleming in 1929. Penicillins are used to treat skin infections, dental infections, ear infections, respiratory tract infections, urinary tract infections, gonorrhea. Penicillins are sometimes combined with other ingredients called beta-lactamase inhibitors, which protect the penicillin from bacterial enzymes that may destroy it before it can do its work.
Penicillins are usually very safe. The greatest risk is an allergic reaction, which can be severe. People who have been allergic to cephalosporins are likely to be allergic to penicillins.
Penicillins block the construction of bacteria cell walls, causing the walls to break down, and eventually killing the bacteria.
The most commonly-prescribed penicillins:
amoxicillin
ampicillin
bacampicillin
oxacillin
penicillin
Tetracyclines
Tetracyclines are a family of antibiotics used to treat a broad spectrum of bacterial infections. Tetracyclines were discovered in the late 1940s and were extremely popular when they were first discovered. The tetracycline antibiotics have a very broad spectrum of action.
Tetracyclines are used to treat mild acne, Rocky Mountain spotted fever, Lyme Disease, upper respiratory tract infections, urinary tract infections, sexually transmitted diseases, typhus.
The most commonly-prescribed tetracyclines:
tetracycline
doxycycline
minocycline
Antibiotic resistance
Antibiotics are extremely important in medicine, but unfortunately bacteria are capable of developing resistance to them. Antibiotic-resistant bacteria are germs that are not killed by commonly used antibiotics. When bacteria are exposed to the same antibiotics over and over, the bacteria can change and are no longer affected by the drug.
Bacteria have number of ways how they become antibiotic-resistant. For example, they possess an internal mechanism of changing their structure so the antibiotic no longer works, they develop ways to inactivate or neutralize the antibiotic. Also bacteria can transfer the genes coding for antibiotic resistance between them, making it possible for bacteria never exposed to an antibiotic to acquire resistance from those which have. The problem of antibiotic resistance is worsened when antibiotics are used to treat disorders in which they have no efficacy (e.g. antibiotics are not effective against infections caused by viruses), and when they are used widely as prophylaxis rather than treatment.
Resistance to antibiotics poses a serious and growing problem, because some infectious diseases are becoming more difficult to treat. Resistant bacteria do not respond to the antibiotics and continue to cause infection. Some of these resistant bacteria can be treated with more powerful medicines, but there some infections that are difficult to cure even with new or experimental drugs.
Antibiotics Friend or Foe?

What is an antibiotic?
     The term "antibiotic" (from the Ancient Greek: anti, "against" and Ancient Greek: bios, "life") Originally meant any substance produced by a micro-organism that is antagonistic to the growth of other micro-organisms in high dilution.The original definition excluded synthetic compounds such as the sulfonamides and naturally occurring substances, such as gastric juice and hydrogen peroxide. In short an antibiotic is is a substance or compound that kills or inhibits the growth of bacteria. They are used to treat infections caused by microorganisms such as fungi and protozoa.
    With advances in medicinal chemistry, many antibiotics are chemically altered from original compounds found in nature. Many more have been created purely synthetic.

     Now that we Know what they are! Where do they come from.

     Antibiotics have been used in treatment of ailments for over 2500 years. Many ancient cultures used molds and plants to treat infections Quinine was used as a therapeutic agent for the treatment of malaria, a disease caused by protozoan parasites. Paul Ehrlich a German medical scientist noted that certain dyes would bind to and coloured human, animal or bacterial cells while others did not.He then Hypothesized that it might be possible to make certain dyes, or chemicals, that would bind to and kill bacteria while not harming the human host. He later discovered the first medicinally useful drug, and man-made antibiotic, Salvarsan. The work of Ehrlich marked the birth of the antibiotic revolution.

     What do they do for us?

    They are designed and used to fight infections throughout our modern culture. For farm animals as well as humans on a ever increasing scale. Most of us have used them at one time or another for soar throats,tooth aches,infected cuts and more. They are now used as much for prevention as for immediate infection. As such with mother natures use of natural selection. Stronger and more resistant strains of bacteria have formed. One of those is The antibiotic-resistant bacteria 'Extended Spectrum Beta Lactamase'(ESBL). ESBL's are actually enzymes produced by certain types of bacteria which create resistance to the antibiotics that are commonly used to treat this form of infection . This particular bacteria is being transmitted to humans through pork in our food supplies.
     Few humans were affected by these mutated bacteria until recently. Now apparently a mutated version of ESBL has appeared.
This new strain is extremely antibiotic resistant and are frequent in urinary tract infections. There were close to 100,000 cases of invasive methicillin-resistant Staphylococcus aureus commonly known as staph in the U.S. in 2005. This particular bacteria lead to over 18,000 deaths. More than AIDS which only accounted for 17,000 deaths.
     Resistance in bacteria to antibiotics can be attributed to the widespread use of them in our agriculture. Placing them in the food sources of our farm animals has indirectly put them in our food supply. Because animals fed antibiotics generally gain approximately 5 % more than animals not fed these bacteria killers it has become a common practice.Using manure from these affected farm animals has also placed them in our fruits and vegetables.
This constant consumption of antibiotics directly or indirectly has created some particularly antibiotic resistant strains of bacteria.

     Now that the double edged sword has been presented how do we avoid unnecessary consumption of antibiotics?

     Health officials state that the main reservoir of these organisms is in the lower digestive tract. It would seem that an answer to the problem of antibiotic resistant strains of bacteria would be very easy to assume. Stop using agricultural products that were fed antibiotics. But as easy as that sounds it is a little more complicated than that.
The drug companies agricultural sales are credited with 70%+ of the total sales worldwide.

     Well why not just eat Organic?

     As previously stated the use of manure as a fertilizer is also a concern for unnecessary antibiotic consumption from our fruits and vegetables. At particular risk are root crops beets potatoes carrots and such. Manure is the main source of fertilizer for organic farmers. Because manure is still allowed under the organic label as such the organic crops are not as clean as they first appear or sound. WE could grow our own crops but that just isn't feasible. Many communities do have agriculture programs available that give you access to healthy, locally grown foods. As a safer alternative to livestock products grass fed are not routinely fed antibiotics. So at this point the conclusion is that organic is good but natural is the best.
Antibiotics For Acne

Many people go to a doctor to get a prescription medication for their acne which usually consists of antibiotics. What is the purpose of an antibiotic? What is an antibiotic for acne? Antibiotics work by stopping and preventing bacteria infection which leads to the formation of many types of acne such as pustules.
There are many popular antibiotics that can be taken to eliminate acne:
1. Tetracycline - This is the most popular and prescribed antibiotic for acne. The dosage for Tetracycline varies according to severity of the acne sufferer's condition. A common dosage is 500 mg twice a day. When the acne condition improves, the dosage can be reduced to 250 mg twice a day. When acne condition further improves, dosage can be further reduced again or it can already be stopped altogether. Different from other kinds of antibiotics, Tetracycline must be taken only with an empty stomach for best performance. It cannot be taken by pregnant women (new born babies will have defects) or for kids under 9.
2. Doxycycline - Doxycycline is similar to Tetracycline. It is a synthetic derivative of Tetracycline and are all under the same family. Doxycycline had shown prove to effectively treat inflammatory acne. Doxycycline is often used for people who do not respond to or cannot tolerate Erythromycin (will be covered below) or tetracycline. The dosage for doxycycline varies from 50 mg to 100 mg also twice a day. Unlike Tetracycline, Doxycycline must be taken with food or else it can cause significant nausea. Doxycycline is more likely to increase sensitivity to the sun and cause sunburns then Tetracycline though.
3. Minocycline - Minocycline is also another synthetic derivative of Tetracycline. It is of a newer generation. While Doxycycline is good in treating inflammatory acne, Minocycline is good in treating pustular kinds of acne eg pustules and cysts. It has shown to be not as prone to antibiotic resistant as the other antibiotics but have higher chances of severe side effects.
4. Clindamycin - Clindamycin is a topical antibiotic instead of an oral one. It is normally used to treat mild to moderate acne but isn't very strong on its own. Clindamycin can work with BP (benzoyl peroxide) or Adapalene (Differin Gel) to have a synergy effect that increases both parties effectiveness but at the same time increase risk of side effects too.
5. Erythromycin - Notice the similarity in the ending of the names of the antibiotics. Erythromycin is known for its effectiveness in reducing inflammation which results in the elimination of bacteria and also the redness caused by acne. It is taken with or after food. The common dosage for Erythromycin is 250mg to 500 mg twice a day.
6. Azithromycin - Azithromycin is a new generation antibiotic which is derived from Erythromycin. There are medical trials that shows tolerability for Azithromycin is better than Erythromycin and Doxycycline. This antibiotic has minimal side effects as compared to others especially the Tetracycline family. It stops inflammation of acne by interfering with bacteria protein synthesis and thus stopping bacteria from multiplying.
The antibiotics all produces common side effects:
Diarrhea
Upset Stomach
Nausea
Dizziness
Vomiting
Abdominal Pains
Candida (acne causing factor, antibiotics actually produces this too)
Vaginal Yeast Infection
Weakening of Birth Control Pills
Skin Redness
Do not be too afraid to take antibiotics though because side effects have a low chance of happening and even when they do happen, it is most of the time mild.
The History of Antibiotics

Almost everyone has used an antibiotic like penicillin or Terramycin at one time or another. You may have tried using an antibiotic ointment for bad cuts or scrapes, or your doctor may have prescribed antibiotics to help you get over fever, boils, pneumonia and other infections. Antibiotics work very well against so many infections that they are often called "miracle drugs". But the more accurate name for them would be "microbe drugs" for that is what antibiotics really are. Antibiotics are essentially chemicals that helped kill or stop the growth of certain germs and bacteria. It comes from two Greek words meaning "against life".
More than 3000 years ago, Asian peoples had already stumbled on molds that could cure certain afflictions. The Indians of Central America as well the Chinese used molds to treat infected wounds in rashes however, they did not understand either diseases or treatments in the way we do now. Many of them thought in terms of magic and spiritualism, so they simply believed that molds drove away evil spirits that cause the disease. As time passed, men had slowly gained some more knowledge of disease. True understanding began only in recent times. In the 1860s, a French scientist Louis Pasteur proved that many diseases were caused by bacteria and concluded that man could learn to fight these bacteria using other bacteria.
Two German doctors, Rudolf Emmerich and Oskar Low, were the first men to make an effective medicine from microbes. Among other things, they successfully proved that the germ that causes one disease can also cure another. The two men took germs from infected bandages and grew them in test tubes. They managed to isolate a vicious germ that caused the green coloring in infected and opened wounds. This bacterium was the Bacillus pyocyaneus. When the doctors placed some of these bacteria into test tubes containing other germs, the Bacillus pyocyaneus would wipe the other germs out. The good news was the other bacteria it managed to wipe out were the bacteria that caused cholera, diphtheria, anthrax and typhoid fever.
Emmerich and Low began to use Bacillus pyocyaneus to make"pyocyanase". This would be the first antibiotic to be used in hospitals, but unfortunately it was ahead of its time. Nobody knew how to control its production or how the chemical worked. It was also noticed that the medicine did not have the same effect on all patients. While some people got better, others only became sicker. So pyocyanase was eventually abandoned.
Other scientists continued to look for a safe and effective antibiotic, but it was only in the summer of 1928 that a research scientist named Alexander Fleming would produce the first real breakthrough in antibiotic medicine. While studying the germ called Staphylococcus aureaus (which causes a number of ailments that lead to brain disease) he noticed that the molds in one of his petri dishes became spoiled. He noticed that around the spot of mold was a germ-free ring of gelatin that meant the mold had killed the germs around it. He did more research and eventually called it penicillin. An American, Dr. Selman Waksman, discovered streptomycin which proved to be effective against diseases that penicillin could not cure, such as the bubonic plague.
At around the same time, sulfa drugs came about. The drug was a chemical that had been found in a substance used to make dyes. These were powerful weapons against disease but had serious drawbacks. It was then found that sulfa drugs did not kill germs but rather weakened germs, which gave the body a chance to defend itself.
Research scientists then began a worldwide search for the most helpful soil microbes. One laboratory discovered Aureomycin and that does the work of both penicillin and streptomycin. Another laboratory discovered Chloromycetin, which was proven effective against typhus, whooping cough and typhoid. In 1949, an Indiana laboratory discovered Terramycin, now considered to be one of the most effective antibiotics ever found because of it's wide effect on so many bacterial diseases.
Even so, the search goes on. Drug companies continue to seek new antibiotics in nature and their chemists are now making synthetic antibiotics. Since it is very difficult for a chemist to imitate the work done by microbes, most antibiotics nowadays are semi-synthetic. Chloromycetin, cycloserine and a synthetic tetracycline were the first few antibiotics that have been produced entirely by man.
Antibiotics - General Information

An antibiotic is the common medical drug that helps in slowing down and killing off the growth of various bacteria. The Antibiotics are the solitary set of the antimicrobials; it is the bigger group that includes the anti-fungal, anti-parasitic drugs and the anti viral. These medications are the normally harmless to the mass, therefore consequently could be worn safely for the treatment of infections of our body. The Antibiotics are the minute molecules that have the molecular power of less than 2000. These days, the term "antibiotic" is applied to the artificial antimicrobials, as sulfa drugs. Before, people used numerous poisonous drugs for the various treatments of the bacteria and its infectivity, and demise rate was a large amount higher at that time. The Antibiotics have shaped the magical wonder for treatment of the infections in the therapeutic field. The Effectiveness of the antibiotics varies along with the place of the disease, capacity of the antibiotic is to attain the location of infection, and the potential of the bacteria to confront or inactivate the antibiotic.
The Antibiotics are frequently taken as oral medications in the form of tablets and powdered form, however sometimes it has been administered topically, in the structure of ointments and eye drops.

The resistance of Antibiotic is the capability of the various micro organisms to tolerate the property of the antibiotics. This antibiotics resistance could develop through the plasmid exchange or the gene action amongst the bacteria of the related species. When a bacterium transmits several of resistant genes, this are called as the multiresistant or it is often described as the 'super bug'. Essentially, the antibiotic resistances develop as a outcome of the natural selection.
The act of the antibiotic is an ecological force, and the bacteria's by means of mutation allows them to stay alive and reproduce. They bypass this character to their young that are all resistant generation.

A feature that contributes to the antibiotic resistance includes the unnecessary prescriptions, the incorrect diagnosis, the inappropriate use of antibiotics in patients, and the use of the antibiotics as livestock foodstuff additives for the development. Contrasting the antibiotics, a vaccine does not make up to the resistance. The Vaccines may work by enhancing the body's standard defenses, while the antibiotics operate in the structure of body's common defenses. Therefore antibiotics are the useful drug for lot of people suffering from various of bacterial infection all over the world.