ANTIBIOTICS Pharmacy - USA Shipping

 

 

Antibiotics kill or inhibit bacterial growth in these ways.

• Interference with Cell Wall Synthesis : The first antibiotic, Penicillin, and many others work by preventing the germs from repairing their cell walls. The cell walls weaken and eventually burst, leading to the cell's death.

• Disruption of Cellular Processes : Erythromycin and Tetracycline prevent cells from making proteins or other essential components. This prevents the cells from growing and multiplying, making it easier for the body's immune system to destroy them.

• Blocking of Metabolism : Antibiotics known as polymyxins prevent germs from taking in nutrients and expelling their own metabolic waste products. This leads to a combination of starving the germ and accumulating toxins that kill it.

• Blocking DNA Synthesis : Ciprofloxacin, Levofloxacin, and other antibiotics in this class prevent the germs from multiplying by interfering with their ability to make DNA.

• Competition with Nutrients : Some germs require the vitamin-like substance para-aminobenzoic acid (PABA) to survive. Sulfa antibiotics are chemically very close in structure to PABA. The germs that require PABA are fooled into picking up the antibiotic rather than the PABA. This inhibits their growth, making it easier for the body's immune system to kill them.

Antibiotics can do more harm than good if they are not used the right way. You can protect yourself and your family by knowing when you should use antibiotics and when you should not.

When germs are exposed to the same antibiotic again and again, the antibiotic stops working. Being exposed to the same antibiotic for a long time can make some germs change. These changes make the germs so strong that they can fight back against antibiotics. Then these germs are said to be "resistant" to this antibiotic. Resistant germs grow faster when antibiotics are used too often or are not used the right way.

 

These are some basic guidelines to determine if you need Antibiotics:

Colds and flu are caused by viruses. They cannot be cured with antibiotics.

 

Cough and bronchitis are almost always caused by viruses. But if these problems do not go away, germs may be the cause.

 

A sore throat is usually caused by a virus and cannot be cured with an antibiotic. But strep throat is caused by germs. Your doctor will do a lab test before prescribing an antibiotic for strep throat.

 

Ear infections can be caused by viruses or germs. Antibiotics sometimes are used for ear infections, but they are not always needed since they do not work for ear infections caused by viruses.

 

Sinus infections can be caused by viruses or germs. Antibiotics sometimes are used to treat sinus infections. But a runny nosewith yellow or green mucus does not always mean you need to take an antibiotic.

 

 

Penicillins and Cephalosporins

Most bacterial cells have double layers on their outside. The outermost layer - the "cell wall" - is similar to the outer layer of plant cells, but is missing in human and animal cells. This wall must grow along with the cell, or the growing cell will eventually become too big for the wall and burst and die. the Antibiotics class of Penicillins and Cephalosporins kill bacteria by destroying or interfering with their wall-building system. Since we don't have cell walls, and plants have a different wall-building system, neither we, nor animals, nor plants are affected by the medicine.

There are a types of bacteria that don't have cell walls. These germs are immune to penicillins and cephalosporins for the same reasons we are. Most bacteria do have cell walls, but many have changed their wall-building systems so that penicillins can't interfere, or have come up with ways to break down the medicines before the medicines can work. These are resistant bacteria or "super germs".

Penicillins and cephalosporins usually don't cause many problems for a patient. Like all antibiotics, they can cause mild side effects like diarrhea. Less common side effects include rashes and Hives; however an outbreak of Hives usually means you're allergic to the medicine.

 

Macrolides

Erythromycin is an antibacterial produced by a mold. There are a couple of new Erythromycin-related macrolides of - Azithromycin and Clarithromycin - that work the same way, but kill more bacteria and have slightly fewer side effects. The Erythromycin-like antibiotics are known as Macrolides.

Macrolides works by blocking the bacterial cell's machinery for making new proteins. Since proteins both make up much of the cell's structure and make the enzymes that direct all the cell's chemical reactions, blocking protein manufacturing makes the cell unable to function. Erythromycin in low doses will stop bacteria from growing and multiplying, but a higher concentration is required to kill the bacteria. However, if the drug can stop growth until the body's immune system kicks in, that will help you get rid of the infection.

Since all protein making is affected, Erythromycin can slow down or kill any bacteria, even those without cell walls. Because of this, we use the Erythromycins for several diseases, including bacterial bronchitis, chlamydia, and whooping cough, that penicillins and cephalosporins can't treat.

Macrolides don't have allergy problems we see with the penicillins and cephalosporins, although there are rare people who have reactions to it. The biggest problem with these medicines is that they can irritate the stomach; this irritation seems to happen most often when someone tries to take the medicine on an empty stomach. Always take Erythromycin with food or milk; the same holds for Clarithromycin. Azithromycin doesn't irritate the stomach nearly as much as the other Macrolides.

 

Sulfanilamides or Sulfonamides

The Sulfas ("sulfanilamides" or "sulfonamides") were the first synthetic antibiotics to be developed; they are completely man-made. Sulfas interfere with certain "manufacturing" systems in the bacterial cell, including ones that bacteria use to produce new DNA for new bacteria. Sulfanilamides can stop bacteria from growing, but they cannot actually kill the bacteria.

When they were first used, Sulfonamides worked against many kinds of bacteria. Unfortunately, as with Penicillin, the more we used the Sulfas the more bacteria became resistant to it. Sulfonamides also have a tendency to produce allergic reactions including some that are rare but life-threatening. Because of this we don't use sulfas nearly as much we used to in the past, and most often when we use sulfas it's in combination with another drug which attacks a different part of the bacteria - an attack on two fronts is usually better than an attack on one. The drugs we usually combine with sulfas are either Erythromycin or Trimethoprim; these combinations usually can kill bacteria rather than just slowing them down.

 

Trimethoprim

Trimethoprim (TMP) is another synthetic antibiotic. Like the Sulfas, TMP blocks an important step in the bacteria's system for making new DNA. By itself, Trimethoprim can kill bacteria, but very slowly. Usually, though, we use TMP in combination with Sulfamethoxazole (SMX), and the combination of TMP and a Sulfa kills bacteria better. In fact, bacteria that are partly resistant to either TMP or SMX can still be killed by the combination of the two. The side effects of the combination are the same as those of the two separate components.

 

Nitrofurantoin

Nitrofurantoin is another synthetic antibiotic, used mainly for urinary tract infections. Nitrofurantoin stops bacteria from growing, and can kill bacteria with a high enough level, by blocking the bacteria's ability to use energy it makes by digesting nutrients like sugar, and by blocking other chemical reactions that use the same system. It is not usually used for infections other than UTIs, and there are several side effects, ranging from stomach upset to (very rarely) malfunctioning nerves, which limit its use.

 

Aminoglycosides

The Aminoglycosides are drugs which stop bacteria from making proteins; they work by attaching permanently to the protein machinery. Since they attach permanently, the bacterial cell will die if it gets enough of the drug. Aminoglycosides can be used by themselves, or along with Penicillins or Cephalosporins to give a two-pronged attack on the bacteria.

Aminoglycosides work quite well, but bacteria are prone to becoming resistant to them. Since Aminoglycosides are broken down easily in the stomach, they can't be given by mouth and must be injected or given intravenously (although we can use them as eyedrops for conjuctivitis). When injected, their side effects include possible damage (temporary or permanent) 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, and in the hospital where we can clinically check both the drug levels and the bacteria's sensitivity.

 

Quinolones

The Quinolones, of which the best known is Ciprofloxacin (Cipro®), interfere with an enzyme called DNA gyrase that is essential for duplication of bacterial DNA. Bacteria have only one long chromosome (DNA molecule) and this chromosome gets twisted during replication and the chromosome can become so twisted that nothing more can be done with it. DNA gyrase is the "untwisting" enzyme for the bacterial chromosome. This interference by Quinolones is completely different from the interference of other antibiotics with bacterial "machinery", and so bacteria that are resistant to other antibiotics will be vlunerable to the Quinolones.

However, bacteria have been known to develop resistance to the Quinolones too. Also, researchers have found that young animals given quinolones can have damage to their cartilage; resultantly we have avoided using quinilones in children because of this finding, but we sometimes have to give some children quinolones when there is no alternative antibiotic available.