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Tetracycline – Effect, Application & Risks


Tetracyclines are drugs from the class of antibiotics . They belong to the broad spectrum antibiotics and are used in bacterial infections .

What is tetracycline?

Tetracyclines are a variety of antibiotics first mentioned by Benjamin Minge Duggar in 1948. The drugs were discovered in the research department of drug manufacturer Pfizer. Tetracyclines were patented in 1955.

Tetracyclines were first isolated from bacterial species. This resulted in chlortetracyclines and oxytetracyclines . The tetracyclines available today are chemically modified derivatives of these original substances. They are more tolerable and also have more favorable pharmacokinetics.

Tetracyclines include doxycyclines , minocyclines , and lymecyclines . These differ in their tolerability and in their pharmacokinetic properties. A derivative of the tetracyclines is tigecycline . This substance is primarily used for severe infections with multi -resistant germs .

Pharmacological action

Tetracyclines bind to a special subunit of the bacterial ribosome . Ribosomes are small cellular particles made up of proteins . They are responsible for protein biosynthesis in the cells . Without this synthesis , the bacteria cannot divide .

Due to the tetracyclines, the aminoacyl-tRNA in particular cannot align itself properly on the 50s underside of the ribosomes. The required peptidyl transferase reaction cannot be performed. Thus, the peptide chain is broken off during protein synthesis in the bacteria . It is possible that the toxicity of the drug is based on a disruption of the 30-S ribosomes, which are present in the mitochondria of the host cells.

Medical Application & Use

The drug is active against gram-positive and gram-negative bacteria. Bacterial genera that do not have a cell wall are also sensitive to the antibiotic. These cell wall-less bacteria include, for example, mycoplasma and chlamydia . Borrelia and spirochetes also react to tetracycline.

Borrelia are the causative agents of Lyme disease . The disease is transmitted by ticks and is associated with dermatological and neurological symptoms. Those affected also suffer from joint pain and constant tiredness . Spirochetes are the causative agents of syphilis . Syphilis is usually transmitted during sexual intercourse . For a long time, the disease had almost disappeared in Germany, but it is currently on the rise again.

A typical indication for tetracycline is pneumonia . The remedy is mainly used in atypical pneumonia. It is also the drug of choice for Q fever . Q fever is a zoonosis caused by the bacterium Coxiella burnetii and is associated with flu-like symptoms.

Tetracycline is also used in infections of the urogenital system. A possible indication here is inflammation of the prostate ( prostatitis ). Skin infections are also typical areas of application for tetracyclines. The drugs are often used to treat acne vulgaris .

Other indications of the drug are plague , cholera , tularemia and brucellosis . Tularemia is transmitted by wild rodents. The causative agent is the bacterium Francisella tularensis . Brucellosis is an infectious disease caused by gram-negative rod-shaped bacteria. It can occur in humans and in animals. Most infections are subclinical. Night sweats , chills and nausea can also occur. Many courses of disease heal spontaneously, but there are also protracted chronic inflammations with serious symptoms such as depressionor persistent insomnia .

Risks & side effects

The main side effects of tetracycline are non-specific stomach and intestinal disorders . Vomiting and nausea in particular are quite common. Neurological dizziness can also be observed. Itching and skin rashes can also occur. Especially at high doses, tetracyclines cause an increase in transaminases. Inflammation of the pancreas ( pancreatitis ) can occur.

The drug not only damages the harmful bacteria. The local flora of the vagina, skin and intestines is also severely affected. Therefore, fungal diseases of the vagina ( vaginal thrush ) and skin ( skin fungus ) can occur, especially after prolonged use. These are also known as candidiasis.

Another serious secondary disease after taking tetracycline is pseudomembranous colitis. This leads to severe inflammation of the large intestine . Damage to the intestinal flora usually manifests itself in the form of indigestion and diarrhea . Pregnant and breastfeeding women should not take tetracycline. The drug gets together with calcium in the bones and in the enamel of the teethof the unborn built in. On the one hand, this discolors the teeth and, on the other hand, the storage of the mineral leads to an increased susceptibility to fracture. Tetracyclines may therefore only be used from the age of ten to twelve.

Since tetracyclines can form complexes with metal ions such as magnesium , iron or aluminum, they must be taken separately from foods containing calcium such as milk or quark. Antacids, magnesium supplements or iron supplements should also not be taken together with the antibiotic.

Women should be aware that tetracyclines can reduce the effectiveness of oral contraceptives . Therefore, additional contraception should be used while taking it. Tetracyclines must not be taken during isotretinoin therapy. Both drugs can dangerously increase intracranial pressure .

Of course, tetracyclines should not be taken in the case of tetracycline intolerance. Otherwise, severe allergic symptoms may appear. In the worst case, allergic shock occurs .

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.