I. Azithromycin Medication
Azithromycin medication is a semi-synthetic macrolide antibiotic chemically related to erythromycin and clarithromycin (Biaxin). It is effective against a wide variety of bacteria organisms, such as Hemophilus influenzae, Streptococcus pneumoniae, Mycoplasma pneumoniae, Staphylococcus aureus, and mycobacterium avium, and many others. It is unusual in that it stays in the body for quite a while, allowing for once a day dosing and for shorter treatment courses for most infections.
Azithromycin medication, like all macrolide antibiotics, prevents bacteria from growing by interfering with their ability to make proteins. Due to the differences in the way proteins are made in bacteria and humans, the macrolide antibiotics do not interfere with humans' ability to make proteins.
Antibiotics/ Antibacterial: Information
The ideal antibacterial or antimicrobial compound displays a selective toxicity. This means that it is harmful to the microbe (the bacteria, fungi or virus) without being harmful to the host (you). In reality, many antimicrobials have a relative toxicity. Antimicrobial is a broader category that includes antifungal, antiviral, antiprotozoal or antibacterial compounds. Antibacterials specifically act against bacterial cells.
The actual mechanism of antibacterial compounds is not always known. In general terms, most of these drugs act by altering or inhibiting one of the following cellular structures/processes:
- cell wall synthesis
- permeability of the cell membrane
- protein synthesis
- nucleic acid synthesis
Classes of Antibacterials
Penicillins: The penicillin class of antibiotics is a diverse, yet highly essential class of antibiotics. The penicillin class includes penicillin G, penicillin V, amoxicillin, ampicillin, nafcillin, ticarcillin (combined with clavulanic acid = Timentin), Augmentin (amoxicillin and clavulanic acid), Zosyn, and many, many others. Penicillins work by damaging the cell wall of the bacteria.
Penicillin (antibiotics) and all of its derivatives come from a mold, Penicillium notatum, which is toxic bluish-green mold often found on old bread. The mold must be carefully processed to produce the penicillin. This compound was discovered by Alexander Fleming in 1929 and was made famous during World War II. These antibiotics are used to treat a variety of infections including strep throat, upper respiratory infections, salmonella (food poisoning), gonorrhea, chlamydia, and many other infections.
Cephalosporins: Cephalosporins are another widely used class of antibiotics. They are similar to penicillins in structure, but in general, can treat a broader range of infections. For example, these antibiotics are used to treat strep throat, cellulitis, E. coli infections, pneumonia, upper respiratory infections, sinus infections and gonorrhea. Cephalosporins act by disrupting the bacterial cell wall.
A few of the medications in this class include:
- cephalexin (Keflex)
- cefazolin (Ancef or Kefzol)
- cefaclor (Ceclor)
- loracarbef (Lorabid)
- ceftriaxone (Rocephin)
- cefotaxime (Claforan)
Sulfa Drugs : Sulfa drugs are the oldest antibiotics available and are also among the best. Sulfa was first used in 1930's. Sulfa drugs include sulfamethoxazole, a component of Bactrim, Sulfasoxazole, and many others. Sulfa drugs are used to treat a variety of infections including urinary tract infections, upper respiratory infections, and pneumonia. Sulfa compounds work by inhibiting nucleic acid (DNA, RNA) synthesis.
Tetracyclines: Tetracyclines are antibiotics often used to treat penicillin-resistant infections. Tetracyclines are often used to treat gonorrhea, chlamydia, lyme disease, rocky mountain spotted fever, and pneumonia.
Tetracyline antibiotics include doxycycline, tetracycline, and minocycline. These compounds are antimicrobial because of their inhibition of bacterial protein synthesis. They bind to the cellular organelles called ribosomes, and interfere with the assembly of bacterial amino acids into proteins.
It is important to take tetracyclines at least 1 hour before or 2 hours after taking an antacid, drinking milk, or taking iron. Antacids, milk (due to its calcium content), and iron decrease the absorption of tetracyclines.
Tetracyclines can cause bone deformities in children, and should not be given to anyone under the age of 8. The most common side effects of tetracyclines include diarrhea, loss of appetite, nausea, vomiting, and sore mouth. Tetracyclines may increase sensitivity to the sun, so avoid prolonged exposure and wear sunscreen when taking such compounds.
Macrolides: Macrolides are a class of drugs that are entirely different from penicillins, but are often used to treat many of the same diseases. Penicillins work by damaging the cell wall of the bacteria. In contrast, macrolides drugs inhibit protein synthesis but by a different mechanism than tetracycline. The structural differences in macrolides drugs also make them ideal alternatives to penicillin in patients who have penicillin allergies.
Macrolides drugs are often used to treat pneumonia, whooping cough, diphtheria, upper respiratory infections, bronchitis, sinus infections, and many other diseases. Examples of macrolides include:
Common side effects with Macrolides include : stomach upset, diarrhea, loss of appetite, and nausea and vomiting.
Fluoroquinolones: Fluoroquinolones are broad-spectrum anti-infectives. They are used to treat a variety of infections, including strep throat, pneumonia, severe upper-respiratory infections, several of the STDs, and some of the severe hospital-acquired infections. Examples of some of the fluoroquinolones are ciprofloxacin (Cipro) and levofloxacin (Levaquin). Ciprofloxacin has been used to treat persons exposed to anthrax in recent bioterrorism events in the US.
Common side effects with Fluoroquinolones include: diarrhea, difficulty sleeping, dizziness, drowsiness, headache, and nausea. To help reduce the side effects, try to take these medications 1 hour before or 2 hours after taking an antacid or drinking milk.
Intravenous (IV) Antibiotics
Aminoglycosides
This class of antibiotics is only available as IV infusions because they are not well absorbed orally. However, they can also be given as a injection into the muscle (such as bicep or thigh).
Aminoglycosides are used to treat a variety of infections, including endocarditis, cellulitis, bronchitis, pneumonia, meningitis, pyelonephritis, severe urinary tract infections, and many other infections. These drugs work by inhibiting bacterial protein synthesis. Examples of aminoglycosides include gentamicin, tobramycin, and amikacin.
Although these drugs are important agents and often are "life-saving" they must be closely monitored due to the potential for serious toxicity. It is important to inform your doctor immediately if any of the following symptoms are noticed while taking an aminoglycoside: difficulty hearing, dizziness, increased thirst, loss of balance, muscle weakness, nausea, pain or difficulty passing urine, or ringing in the ears. In particular, these compounds can be toxic to components of the nervous system, kidneys and ears.
Glycopeptides
Currently, there is only one drug in this class of antibacterials: vancomycin (Vancocin). Intravenous vancomycin is used to treat a variety of severe infections, such as penicillin-resistant pneumonia, methicillin-resistant Staphylococcus aureus-a serious bacterial infection that is extremely difficult to treat, and other serious infections.
Vancomycin is also available orally, but the oral form of the drug is not absorbed well. Because it remains largely in the gut, vancomycin is one of two antibiotics used to treat pseudomembranous colitis, an inflammation of the large and small intestine caused by the effects of other antibiotics.
The most common side effects of oral vancomycin are nausea and vomiting.
Intravenous vancomycin is given primarily under the direct supervision of a healthcare provider. Common side effects from the IV include nausea, vomiting, and pain at the injection site.
Streptogrammins
This is the newest class of antibiotics on the market. Currently, there is only one drug in this class of antibacterials: the combination drug Quinupristin/Dalfopristin (Synercid).
Synercid was specifically designed to treat infections that vancomycin is unable to treat. For example, Synercid was designed to treat vancomycin-resistant enterococcus (VRE), a life-threatening, hospital-acquired infection. Synercid is currently reserved for severe infections, and is available only as an IV.
Microbes: Information
Microbes are the oldest form of life on Earth. Some types have existed for billions of years. These single-cell organisms are invisible to the eye, but they can be seen with microscopes. Microbes live in the water you drink, the food you eat, and the air you breathe. Most microbes are helpful and some even essential, like the billions of microbes swimming in your intestines to help digest food and create the essential vitamins our bodies need. Billions more live naturally in our skin, mouth, nose, teeth, throat, and urethra. In fact, 95% of all microbes are not harmful.
Humans, microbes, and other living creatures all share the environment and interact in ways that allows them to coexist. Microbes' mission in life is to reproduce and do whatever it takes to survive. They have the ability to evolve rapidly and can adapt to changing conditions, but where any particular microbe can live depends on its biological requirements. Some, like the hantavirus microbe, are limited to the habitat of the animals that carry them for part of their life cycle. Some have evolved to exist in more than one habitat: different flu viruses can survive in humans, birds, and other animals, and can even withstand drying out on an exposed surface. Others are far more specialized and can survive in only one type of environment. Deadly and widespread as it is, HIV cannot exist for long outside the human body, for example.
Some disease-causing microbes enter the human body and stay there for part or all of their life cycle. When pathogenic microbes spend part of their lives in insects or other animals before they move to the human body, they are called vector-borne agents. Some microbes that live in water are harmful if swallowed, or if they penetrate the skin. Soil microbes can enter the human body through a break in the skin or can be inhaled as dust.
There are five types of microbes: bacteria, viruses, protozoans, fungi, and helminths (worms).
1). Bacteria
[Diagram 1 : Bacteria pictured clockwise from top: E. coli (causes food poisoning), Strepococcus pyrogenes (causes strep throat), Mycobacterium tuberculosis (causes tuberculosis)]
The most abundant organisms on Earth, bacteria live almost everywhere: in the soil and water, in plants and animals. Whether they take the form of spheres, rods or spirals, bacteria consist of a single cell. Unlike the cells of animals and plants, bacterial cells lack a nucleus, but they can carry out all necessary life functions. Most bacteria are parasites, although a few manufacture their own food. Some of these parasites are very helpful they aid in many bodily functions including digestion, and help with other processes, such as decomposition of soil and changing of milk into cheese. Disease results, however, when bacteria multiply rapidly (each cell simply divides into two identical cells) and damage or kill human tissue, as in pneumonia and tuberculosis. Diseases can also produce toxins that damage or kill human tissue, as in food poisoning or cholera. Sometimes bacteria in the body are helpful for a while, and then something in the body or the bacteria changes, causing destruction in the host.
2). Viruses
[Diagram 2: Viruses pictured clockwise from top: Adenovirus (causes the common cold), Influenza A (causes the flu), and Hepadnavirus (causes hepatitis B)]
By far the smallest microbes, viruses can appear as spirals, 20-sided figures or even more complicated forms. They consist mainly of genetic material-DNA or RNA. They are not cells, however, and cannot carry out life functions on their own. Living inside the cells of other species, viruses use the host cells to grow and produce new viral particles. As they take over genetic material to reproduce themselves, the host cells often die. Found in all groups of living things, from bacteria and fungi to plants and animals, hundreds of the known viruses can cause many kinds of infections, chickenpox, measles, flu, colds, polio, and AIDS. Viruses cannot move by themselves and must be carried to cells by air currents and then by body fluids to the cells. Some viruses may lay dormant for years before becoming active, as with AIDS. Most diseases come from other species, for example: smallpox from dogs or cattle, hemorrhagic fevers from rodents and monkeys, tuberculosis from cattle and birds, common cold from horses, and AIDS from African monkeys.
3). Protozoa
[Diagram 3: Protozoa pictured clockwise from top: Giardia intestinalis (causes diarrhea), Trypanosoma brucei (causes sleeping sickness), Plasmodium gametocyte (causes malaria)]
Protozoa consist of a single cell that includes a nucleus. The cell also contains structures that carry out specific processes needed for life functions. A diverse and complex group, protozoa range through many shapes and sizes. They can be parasitic, needing to live within another organism, or free-living in moist habitats. The similarity of inner structures of protozoan and human cells makes it difficult to treat infections caused by protozoa. Drugs that may destroy the protozoan may also destroy human cells. Protozoan infections include amebic dysentery, malaria, and African sleeping sickness.
4). Helminths
[Diagram 4: Helminths pictured left to right: Ascaris lumbricoides (an intestinal roundworm), Schistosoma mansoni (a parasitic worm that lives in contaminated water and causes schistosomiasis or bilharzia)]
Other microorganisms break down body tissues or absorb digested food. They can cause anything from skin infections to internal disorders that can lead to death. The group called helminths includes flukes, roundworms, and tapeworms; these are many-celled animals with developed organs. Among the numerous types, some are parasites-organisms that live in or on another species, usually harming the host species in the process. Because of their size, parasitic worms grow outside of cells and can reach an astronomical size of 30 feet in length.
5). Fungi
[Diagram 5: Fungi pictured left to right: Histoplasma capsulatum (causes histoplasmosis, a lung infection), Penicillium notatum (produces the drug penicillin)]
Fungi include yeasts (one-celled), and mushrooms and molds (multi-celled). Unlike plants, fungi do not make their own food. Some species of fungi get their nutrition by breaking down remains of dead plants or animals. Others are parasites. Examples of fungal infections include athlete's foot and ringworm.
Side effects of Antibacterials (Antibiotics)
The most common side effects with antibiotic drugs are diarrhea, feeling sick and being sick. 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.
Rare, but more serious side effects, include the formation of kidney stones with the sulphonamides, abnormal blood clotting with some of the cephalosporins, increased sensitivity to the sun with the tetracyclines, blood disorders with trimethoprim, and deafness with erythromycin and the aminoglycosides.
Sometimes, particularly in older people, antibiotic treatment can cause a type of colitis (inflamed bowel) leading to severe diarrhoea. Penicillins, cephalosporins and erythromycin can all cause this problem but it is most common with clindamycin, an antibiotic usually reserved for serious infections. If you develop diarrhea while taking an antibiotic, immediately contact your doctor.
Some people are allergic to antibiotics, particularly penicillins, and can develop side effects such as a rash, swelling of the face and tongue, and difficulty breathing when they take them. Always tell your doctor or pharmacist if you have had an allergic reaction to an antibiotic; sometimes the reaction can be serious or even fatal. This is called an anaphylactic reaction.
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III. Useful links
Government http://www.medicinenet.com/azithromycin/article.htm
http://www.cdc.gov/
http://www.fda.gov/
http://www.fda.gov/cder/ogd/
http://www.nih.gov/
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi
http://www.health.gov.on.ca/
National Library of Medicine
World Health Organization
Health Sites
http://www.mayoclinic.com/index.cfm
MedicineNet.com
Drugdigest.org
Healthsquare.com
Pharmacy sites
http://www.healthdigest.org/Bactrim-DS(Oral)_2006_PRO.php
http://www.hsforum.com/stories/storyReader$1509
http://www.hsforum.com/stories/storyReader$1504
http://www.people.vcu.edu/~urdesai/atc.htm#Process%20of%20clotting
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