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

What is tetracycline?

Tetracyclines are drugs from the drug class of antibiotics. They belong to the broadband antibiotics.

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

Tetracycline was first isolated from bacterial species. This created Chlortetracycline and Oxytetracycline. The tetracyclines available today are chemically modified derivatives of these original substances. They have a higher tolerability and also have a more favorable pharmacokinetics.

The tetracyclines include doxycycline, minocycline and lymecycline. These differ in their tolerability and in their pharmacokinetic properties. A derivative of the tetracyclines is tigecycline. This substance is mainly used in severe infections with multidrug-resistant bacteria.

Pharmacological action

Tetracycline binds to a special subunit of bacterial ribosomes. Ribosomes are small cellular particles that consist of proteins. They are responsible for protein biosynthesis in the cells. Without this synthesis, a division of the bacteria is not possible.

In particular, the aminoacyl tRNA on the 50s bottom side of the ribosomes can not align properly with the tetracyclines. The required peptidyl transferase reaction can not be performed. Thus, during protein synthesis in the bacteria, the peptide chain breaks down. The toxicity of the drug may be due to elimination of the 30 S ribosomes present in the mitochondria of the host cells.

Medical application & use

The drug works against Gram-positive and Gram-negative bacteria. Even bacterial genera that have no cell wall are sensitive to the antibiotic. These cell-wall-free bacteria include, for example, mycoplasma or chlamydia. Borrelia and spirochetes also react to tetracycline.

Borrelia is the causative agent 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 fatigue. Spirochetes are the causative agents of syphilis. The syphilis is usually transmitted during sexual intercourse. For a long time, the disease was almost gone in Germany, but it is currently on the rise again.

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

Tetracycline is also used in infections of the genitourinary system. A possible indication here is the inflammation of the prostate (prostatitis). Also infections of the skin are typical applications for tetracyclines. Thus, the drugs are often used for the treatment of acne vulgaris.

Other indications of the drug are plague, cholera, tularemia and brucellosis. Tularemia is transmitted by free-living rodents. Pathogen is the bacterium Francisella tularensis. Brucellosis is an infectious disease caused by Gram-negative rod bacteria. It can occur in humans and in animals. Most infections are subclinical. It can also come to night sweats, chills and nausea. Many illnesses heal spontaneously, but there are also protracted chronic inflammations associated with severe symptoms such as depression or constant insomnia.

Risks & Side Effects

The main side effects of tetracycline are nonspecific gastric and intestinal complaints. In particular, vomiting and nausea are quite common. Also neurological dizziness can be observed. It can also cause itching and rashes. Especially at high doses tetracyclines cause an increase in transaminases. It may cause inflammation of the pancreas (pancreatitis).

The drug not only damages the harmful bacteria. The locus flora of the vagina, skin and intestine is severely impaired. Especially with prolonged use, it may therefore come to fungal diseases of vagina (vaginal fungus) and skin (skin fungus). These are also called candidoses.

Another serious sequelae after taking tetracycline is pseudomembranous colitis. This leads to a strong inflammation of the colon. The damage to the intestinal flora is usually in the form of indigestion and diarrhea. Pregnant and breastfeeding women should not take Tetracycline. The drug is incorporated with calcium together in the bones and in the enamel of the unborn child. As a result, on the one hand, the teeth discolor and on the other hand, the storage of mineral leads to an increased susceptibility to fracture. Tetracyclines may therefore only be used from the tenth to twelfth year of life.

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

Women should be aware that tetracyclines may reduce the effects of oral contraceptives. During the intake should therefore be additionally used. Tetracyclines should not be taken during an isotretinoin therapy. Both medicines can increase the intracranial pressure dangerously.

Of course, tetracyclines must not be taken in case of tetracycline intolerance. Otherwise, you may experience severe allergic symptoms. In the worst case it comes to allergic shock.