What are antibiotics

Antibiotics are medicines that are used to treat infections caused by micro-organisms (also known as microbes or germs). There are several types of microbes, namely bacteria, viruses, fungi, and parasites and hence there are many types of antibiotics, namely antibacterials, antivirals, antifungals, and antiparasitics.

A bacterium is a specific type of micro-organism that is distinct from a virus, fungus, or parasite. There are billions of bacteria that live on our skin, airways and in our gut without causing infection. These bacteria are called normal flora. Others may cause disease and are therefore referred to as pathogens. Such pathogens may cause infections ranging from superficial skin lesions to sore throat to serious and life-threatening infections of the internal organs, such as pneumonia or meningitis. While the terms antibiotic and antibacterial are often used interchangeably, antibacterial is the more precise term.

The introduction of antibiotics to assist with the fight against infections can be considered one of the most significant medical achievements of the 20th century. In the United States of America (USA), it is reported that, prior to the introduction of antibiotics, 90 % of children with bacterial meningitis (infection of the membranes protecting the brain) succumbed to the disease, while those that survived often had severe and permanent disabilities, including deafness and mental retardation. Bacterial infections of the throat (also called strep throat because it is a result of infection with a bacterium called Streptococcus) could also be fatal, while many people died from tuberculosis, pneumonia, whooping cough or wound infections. With the introduction of antibiotics, many of these once-lethal infections became readily curable.

History of antibiotics

Antibiotics are key to the concept of ‘chemotherapy’. This term was first used by Paul Ehrlich, a German physician who played a pivotal role in the discovery of antibiotics, in the late 1800’s when he coined it to refer to the use of a chemical to treat a disease. With his work, the modern era of antimicrobial chemotherapy began. The word ‘antibiotics’ was only introduced by Selman Waksman, an Ukrainian-American inventor, a good 30 years later. In his lifetime, Waksman discovered more than 20 antibiotics. Erlich, however, introduced the concept of a so-called ‘magic bullet’ – a chemical that would selectively target disease-causing microbes without harming the human host. Through his work and with the help of co-workers the first successful treatment for syphilis was introduced in the early twentieth century.

Although one may think that antibiotics are relatively new since their widespread production only started in the 1940’s, they have actually been used for millennia to treat infections, even though bacteria were only identified as the causative agents during the last century. There is evidence that the ancient Egyptians applied mouldy bread to infected wounds, while traces of what we call tetracyclines (a type of antibiotic nowadays used for, amongst others, malaria prophylaxis and skin infections) have been found in human skeletal remains from Sudanese Nubia, which can only be explained by exposure to tetracycline-containing materials in the diet of these ancient people.

Today we consider Alexander Fleming to be one of the fathers of antibiotics. He inadvertently left a container in which he was culturing bacteria (called a petri dish) uncovered in his laboratory at St. Mary’s hospital in London when he went on holiday in 1928 and, when he came back, he noticed that a fungus had started to grow on it. Remarkably, the fungus had created bacteria-free zones where it grew and, upon further investigation and exploration, Fleming found that the fungus produced a substance that was extremely effective in preventing the growth of the bacteria – even at very low concentrations. Not only that, but it was also less toxic than the disinfectants used at the time. Fleming named this substance penicillin after the name of the mould Penicillium that produced it.

After the initial discovery, it was not long before pharmaceutical companies obtained the expertise to produce antibiotics on a large scale. Antibiotics were used widely to treat soldiers who suffered from wound infections or pneumonia during the Second World War. By the end of the 1940’s, antibiotics became available to the general public. Today, doctors have a wide variety of antibiotics to choose from – all in the effort to combat infectious disease.

How do antibiotics work?

Some antibiotics kill bacteria directly because they interfere with some processes critical to their survival. Penicillin, for instance, interfere with bacterial cell wall synthesis and when the integrity of the bacterial cell wall is compromised, the content may leak out or the cell wall may disintegrate. Antibiotics that kill bacteria directly are called bactericidal antibiotics. Other antibiotics stop bacteria from multiplying and thus provide the body’s own immune system the opportunity to destroy the bacteria. Antibiotics that slow the growth of bacteria without killing them are called bacteriostatic antibiotics.

Broad-spectrum antibiotics are able to treat infections from a wide range of bacteria, whereas narrow-spectrum antibiotics are only effective against a few types of bacteria.

Common side effects of antibiotics

Although there are several different types of antibiotics and not all are the same, generally speaking antibiotics may cause the following side effects amongst others:

  • Diarrhoea
  • Nausea and/or vomiting
  • Skin rash
  • Stomach upset
  • Yeast infections of the mouth, digestive tract, or vagina (known a thrush)

Less commonly, certain antibiotics may also cause the following side effects:

  • Sulphonamide antibiotics may give rise to kidney stones
  • Cephalosporin antibiotics may cause abnormal blood clotting
  • Tetracycline antibiotics may cause sensitivity to sunlight presenting with a skin rash on sun-exposed areas
  • Trimethoprim use may lead to blood disorders
  • Aminoglycoside use may cause deafness
  • Several antibiotics, but especially penicillins, may cause allergic reactions
  • Many broad-spectrum antibiotics may lead to infection with a bacterium called Clostridium difficile which causes diarrhoea, and which may give rise to severe colon damage that may become life-threatening.

A doctor will always weigh the risks of side effects against the seriousness of the infection when it comes to the choosing the most appropriate antibiotic. Sometimes, with life-threatening infections, one will risk a serious side effect to save a patient’s life. If you do experience side effects from taking antibiotics, please make sure that you inform your doctor or pharmacist.


The problem with antibiotics: resistance

While the successes achieved with the use of antibiotics can be considered phenomenal, the emergence of antibiotic resistance has tempered the excitement about antibiotics over recent years. Antibiotic resistance is when bacteria no longer respond to antibiotics or escape the mechanism of action of the antibiotic. When this happens, the usefulness of the antibiotic comes into question, and it makes serious infections all the more difficult to treat. While some infections may become difficult, and sometimes impossible to treat, antibiotic-resistant infections are further troublesome because they require extended hospital stays, additional follow-up visits to the doctor, and they may call for costly and more toxic treatment alternatives.

While Alexander Fleming and Gerhard Dogmagk (the father of sulphonamide antibiotics) were pioneers in the discovery of antibiotics, they were also the first people to predict the rise of antibiotic resistance. Today, antibiotic resistance has become a major public health crisis due to the seriousness of its impact on health (where certain infections cannot be treated with currently available antibiotics) and the limited pipeline of new antibiotics. It is reported that, in the USA, at least 23 000 people die each year as a direct result of infections caused by antibiotic-resistant bacteria.

The dilemma underlying the development of antibiotic resistance is that every time antibiotics are used, it can contribute to the development of resistance. The reason for this is that antibiotic resistance is driven by a combination of bacteria being exposed to antibiotics as well as the spread of these bacteria and their mechanisms of resistance. In other words, when bacteria are exposed to antibiotics, some of them will adapt and obtain mechanisms through which they can escape the harmful effects of the antibiotic in question. These bacteria, which are now resistant to the antibiotic, can then go on to infect other people who have not used the antibiotic previously. Unfortunately, in today’s world, too many antibiotics are being used unnecessarily and when this happens, the bacteria are given the opportunity to develop resistance without the patient experiencing any real benefit.

What is antibiotic stewardship?

To address the healthcare threat posed by antibiotic resistance, antibiotic use has been identified as the most important modifiable factor. To this end, antibiotic stewardship programs have been introduced with the aim to improve antibiotic use. An antimicrobial stewardship program can be defined as a coordinated program that promotes the appropriate use of antimicrobials, improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multi-drug resistant organisms.

Broadly speaking, antibiotic stewardship encompasses all efforts in doctors’ rooms, hospitals, clinics, or long-term care facilities to ensure that antibiotics are used only when necessary and appropriate. This involves prescribing the right antibiotic at the right dose at the right time for the right duration of treatment.

Antibiotic stewardship programs have been shown to be highly successful. Results from studies have demonstrated that antimicrobial stewardship programs successfully meet their aims in that they not only improve patient outcomes, but they can also reduce adverse events from antibiotic use, reduce hospital admission rates as well as, very importantly, reduce antibiotic resistance.

What is my responsibility?

Each and every patient receiving antibiotics to treat a bacterial infection has a role to play in improving antibiotic use.

The best that one can do is to use antibiotics smartly. When antibiotics are used appropriately, patients are provided with the best treatment when they are sick, and they are protected from harms caused by unnecessary use of antibiotics. In addition, the appropriate use of antibiotics helps to combat antibiotic resistance.

It is important that you always use antibiotics according to the following principles:

  1. ONLY take antibiotics when they are really needed.

Antibiotics are only effective when it comes to the treatment of infections caused by bacteria, such as strep throat, whooping cough, and urinary tract infections. They are not effective for viral infections, such as colds and runny noses (even if the mucous or is thick, yellow, or green), most sore throats (with the exception of strep throat), the flu and most cases of chest cold (or bronchitis). In addition, even some bacterial infections, such as many sinus infections and some ear infections, may also heal without the use of antibiotics. Never pressurise a doctor to prescribe an antibiotic if he/she is of the clinical opinion that antibiotics will not be helpful. Taking antibiotics when they are not required still exposes the user to potentially harmful side effects.

  1. Always use antibiotics EXACTLY as prescribed.

Once prescribed, always take antibiotics exactly as instructed by your doctor or pharmacist.

Do not share your antibiotics with others, even if their symptoms are similar.

Do not save antibiotics for later, even if you are feeling better. Ensure that you complete the course. Return all unused medicines to your pharmacist.

Do not take antibiotics that were prescribed for someone else, as this may be the wrong type of antibiotic for the bacteria in question, it may cause dangerous side effects, the antibiotics may interact with some of the (chronic) medicines you are taking, or you may develop side effects.

  1. Always inform your doctor if you experience side effects or develop an allergic reaction while taking an antibiotic.

Your doctor will carefully weight the risk of prescribing an antibiotic versus the seriousness of the infection as well as possible side effects. It is important to tell your doctor if you experienced side effects or suffered an allergic reaction following the use of an antibiotic.

  1. Speak to your doctor or pharmacist about suggestions on how to feel better if an antibiotic is not required.

While one may not require an antibiotic, there may be other medicines that may help to improve your symptoms or to make you recover more quickly. These may include over-the-counter medicines or medicines available without a prescription. Ask your doctor or pharmacist for advice.

  1. Do your best to remain healthy and to look after the health of others by following some basic principles:

Clean your hands regularly.

Cover your mouth and nose when coughing or sneezing.

Stay home when you are sick. Do not go to work and ask someone to do the necessary shopping.

Avoid touching your eyes, nose, and mouth with unwashed hands.

Avoid close contact with people who have colds, or other upper airway infections.

Get recommended vaccines, such as the flu vaccine.


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Antibiotics and Antibiotic Stewardship by topic

These articles are for information purposes only. It cannot replace the diagnosis of a healthcare provider. Pharma Dynamics gives no warranty as to the accuracy of the information contained in such articles and shall not, under any circumstances, be liable for any consequences which may be suffered as a result of a user’s reliance thereon.

The information the reader is about to be referred to may not comply with the South Africa regulatory requirements. Information relevant to the South African environment is available from the Company and in the Professional Information/Patient Information Leaflet/Instructions for Use approved by the Regulatory Authority.

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