Amoxicillin belongs to the group of aminopenicillins and is used as a broad-spectrum antibiotic. The active ingredient has been approved since 1981 and has since been available under various trade names. The drug is effective against both gram-negative and gram-positive bacteria.
What is amoxicillin?
Amoxicillin belongs to the group of aminopenicillins and is used as a broad-spectrum antibiotic. Amoxicillin is a so-called β-lactam antibiotic from the penicillin class of drugs. Its molecular structure contains a lactam ring, which mediates the antibiotic activity of the active substance. The drug has a broad spectrum of application against a wide variety of bacterial species. Sometimes combined use of amoxicillin with clavulanic acid can further increase its range of action. Amoxicillin has a bacteriocidal effect, i.e. it kills bacteria, in contrast to bacteriostatic antibiotics, which have a growth-inhibiting effect. The active substance class of penicillins only destroys bacteria, but not animal and plant cells. The reason is the completely different structure of the respective cell membranes. Thus amoxicillin, like all penicillins, is relatively harmless to the human body. Amoxicillin is also relatively acid-resistant and can therefore be administered orally without losing its effect.
Pharmacological action
The action of amoxicillin is based on the interaction of the lactam ring with the cell membrane of bacteria. Both Gram-positive and Gram-negative bacteria contain the so-called polysaccharide peptide murein in their cell membrane as a constituent. The lactam ring of the antibiotic forms peptide bonds with the murein and thus destroys the membranes of the bacteria. The membrane-destroying effect occurs, among other things, during cell division. During this process, the bacteria die. Some bacteria, such as staphylococci, produce the enzyme β-lactamase, which inactivates amoxicillin by destroying the ß-lactam ring. Therefore, the use of amoxicillin alone is ineffective against staphylococci. However, combined administration of amoxicillin with clavulanic acid can extend its spectrum of activity to this bacterial species. Clavulanic acid, in fact, inhibits the enzyme β-lactamase in its action. When antibiotics are used, including amoxicillin, resistance slowly develops. These resistances are caused by the development of insensitivity of binding proteins to penicillin, by the strengthening of bacterial cell membranes, or by the increased production of the enzyme ß-lactamase. For at least this third type of resistance, combined administration of amoxicillin with clavulanic acid has found a way to combat the bacterium after all.
Medical application and use
Amoxicillin, as mentioned above, has a wide range of uses against various types of bacteria. Unlike classical penicillin, amoxicillin is also effective against Gram-negative bacteria. In contrast to gram-negative bacteria, gram-positive bacteria have a much thicker murein layer in their membrane. The determination of the Gram stain is often performed for this reason, in order to find the appropriate antibiotic for use. However, due to the broad-spectrum activity of amoxicillin, this test is not necessary here. Thus, in addition to the classic use of penicillin, amoxicillin can also be used against Escherichia coli, Listeria, Enterococci and various Proteus species. Thus, many infectious diseases of the upper respiratory tract, ear (otitis media), urinary tract, and gastrointestinal tract are treatable with amoxicillin. By combining amoxicillin with clarythromycin (bacteriostatic antibiotic), infections with Helicobacter pylori in the stomach can also be treated. This bacterium is responsible for gastritis and stomach ulcers, among other things. People with heart disease are often treated with amoxicillin as a preventive measure before surgery. During treatment, amoxicillin is administered mainly orally, independently of food intake, with the body absorbing 80 percent of the active ingredient. Most of the active ingredient is excreted by the kidneys.
Risks and side effects
In general, amoxicillin is well tolerated. It damages the intestinal flora less than other antibiotics. The drug is broken down quickly. However, as with all medicines, side effects are to be expected in some cases when using amoxicillin.Skin rashes, stomach discomfort, nausea, vomiting, flatulence and diarrhea may occur. Itching, fever, inflammation of the mucous membranes, dry mouth and impaired sense of taste are also observed. In rare cases, edema, anemia, liver disorders or even kidney inflammation occur. A penicillin allergy with anaphylactic shock can have a particularly dramatic effect. In this case, therapy with amoxicillin must be discontinued immediately. Continuous use may result in superinfection with resistant strains of bacteria or yeasts.
