What Are Antibiotics? How Do Antibiotics Work?
Last updated on Monday 2 September 2013
Originally published on Monday 20 April 2009
Editors' Choice
Antibiotics are used to treat infections caused by bacteria. Bacteria are microscopic organisms, some of which may cause illness. The word bacteria is the plural of bacterium.
Such illnesses as syphilis, tuberculosis, salmonella, and some forms of meningitis are caused by bacteria. Some bacteria are harmless, while others are good for us.
Before bacteria can multiply and cause symptoms, the body's immune system can usually destroy them. We have special white blood cells that attack harmful bacteria. Even if symptoms do occur, our immune system can usually cope and fight off the infection. There are occasions, however, when it is all too much and some help is needed.....from antibiotics.
The first antibiotic was penicillin. Such penicillin-related antibiotics as ampicillin, amoxicillin and benzylpenicilllin are widely used today to treat a variety of infections - these antibiotics have been around for a long time. There are several different types of modern antibiotics and they are only available with a doctor's prescription in industrialized countries.
According to Medilexicon's medical dictionary, Antibacterial means:
"Destructive to or preventing the growth of bacteria."
There is concern worldwide that antibiotics are being overused. Antibiotic overuse is one of the factors that contributes towards the growing number of bacterial infections which are becoming resistant to antibacterial medications. According to the CDC (Centers for Disease Control and Prevention), outpatient antibiotic overuse in the USA is a particular problem in the Southeast.
According to the ECDC (European Centre for Disease Prevention and Control), antibiotic resistance continues to be a serious public health threat worldwide. In a statement issued in 19th November 2012, the ECDC informed that an estimated 25,000 people die each year in the European Union from antibiotic-resistant bacterial infections.
New ECDC data has shown that there has been a considerable increase over the last four years of combined resistance to multiple antibiotics in E. coli and Klebsiella pneumoniae in over one third of EU and EEA (European Economic Area) nations. Consumption of carbapenems, a major class of last-line antibiotics, increased significantly from 2007 to 2010.
How do antibiotics work?
Although there are a number of different types of antibiotic they all work in one of two ways:- A bactericidal antibiotic kills the bacteria. Penicillin is a bactericidal. A bactericidal usually either interferes with the formation of the bacterium's cell wall or its cell contents.
- A bacteriostatic stops bacteria from multiplying.
What are antibiotics for?
An antibiotic is given for the treatment of an infection caused by bacteria. Antibiotics target microorganisms such as bacteria, fungi and parasites. However, they are not effective against viruses. If you have an infection it is important to know whether it is caused by bacteria or a virus. Most upper respiratory tract infections, such as the common cold and sore throats are generally caused by viruses - antibiotics do not work against these viruses.If antibiotics are overused or used incorrectly there is a chance that the bacteria will become resistant - the antibiotic becomes less effective against that type of bacterium.
A broad-spectrum antibiotic can be used to treat a wide range of infections. A narrow-spectrum antibiotic is only effective against a few types of bacteria. There are antibiotics that attack aerobic bacteria, while others work against anaerobic bacteria. Aerobic bacteria need oxygen, while anaerobic bacteria don't.
Antibiotics may be given beforehand, to prevent infection, as might be the case before surgery. This is called 'prophylactic' use of antibiotics. They are commonly used before bowel and orthopedic surgery.
What are the side-effects of antibiotics?
Below is a list of the most common side-effects of antibiotics:- Diarrhea - researchers from Stanford University School of Medicine found that a rise in sugars in the gut following antibiotic treatment allows harmful bacteria to get a foothold and cause infection. Harmful bacteria thrive on sugar.
- Feeling and being sick.
- Fungal infections of the mouth, digestive tract and vagina.
- Formation of kidney stones (when taking sulphonamides).
- Abnormal blood clotting (when taking some cephalosporins).
- Sensitivity to sun (when taking tetracyclines).
- Blood disorders (when taking trimethoprim).
- Deafness (when taking erythromycin and the aminoglycosides).
In August 2012, Scientists from the NY School of Medicine found that babies who are exposed to antibiotics have a greater risk of becoming overweight or obese children. Their study was published in the International Journal of Obesity.
Visit our specialized news sections
MRSA News
Biology / Biochemistry News
Infectious Diseases / Bacteria / Viruses News
Tropical Diseases News
Bioterrorism News
Allergic reactions to antibioticsMRSA News
Biology / Biochemistry News
Infectious Diseases / Bacteria / Viruses News
Tropical Diseases News
Bioterrorism News
Some patients may develop an allergic reaction to antibiotics - especially penicillins. Side effects might include a rash, swelling of the tongue and face, and difficulty breathing. If you have ever had an allergic reaction to an antibiotic you must tell your doctor and/or pharmacist. Reactions to antibiotics can be very serious, and sometimes fatal - they are called anaphylactic reactions.
Use antibiotics with extreme caution and ensure you inform your doctor/pharmacist if:
- You have reduced liver or kidney function.
- You are pregnant
- You are breastfeeding
Antibiotics may clash (interact) with other medicines
If you are taking an antibiotic do not take other medicines or herbal remedies without telling your doctor first. OTC (over the counter, non-prescription) medicines might also clash with your antibiotic.Penicillins, cephalosporins, and some other antibiotics may undermine the effectiveness of oral contraceptives. If the antibiotic has caused diarrhea/vomiting the absorption of contraceptives may also be disrupted. If you are taking any of these drugs you should consider taking additional contraceptive precautions.
How to use antibiotics
Antibiotics are usually taken by mouth (orally); however, they can also be administered by injection, or applied directly to the affected part of the body.Most antibiotics start having an effect on an infection within a few hours. It is important to remember to complete the whole course of the medication to prevent the infection from coming back. If you do not complete the course, there is a higher chance the bacteria may become resistant to future treatments - because the ones that survive when you did not complete the course have had some exposure to the antibiotic and may consequently have built up a resistance to it. Even if you are feeling better, you still need to complete the course.
Some antibiotics should not be consumed with certain foods and drinks. Others should not be taken with food in your stomach - these would normally be taken about an hour before meals, or two hours after. It is crucial that you follow the instructions correctly if you want the medication to be effective. If you are taking metronidazole do not consume alcohol. Dairy products should not be consumed if you are taking tetracyclines, as they might affect the absorption of the medication.
News that may also interest you
For the latest news and research please visit the following sections:Infectious Diseases / Bacteria / Viruses
MRSA / Drug Resistance
Written by Christian Nordqvist
Original article date: 27th June 2007. Article updated: 27th November 2012.
Did you test my new article? how is rhinoplasty performed I desire you'll adore it :)
ReplyDelete