tetrasykliinien

Tetrasykliinien are a class of broad-spectrum antibiotics that inhibit bacterial protein synthesis by reversibly binding to the 30S ribosomal subunit, interfering with the attachment of aminoacyl-tRNA to the ribosome A site. They are typically bacteriostatic and have extensive tissue distribution. The class includes tetracycline and its most widely used derivatives such as doxycycline, minocycline, and others.

Their activity covers many Gram-positive and Gram-negative bacteria as well as atypical pathogens including Chlamydia, Mycoplasma, and Rickettsia. Clinically, tetrasykliinien are used for acne, certain respiratory and sexually transmitted infections, tick-borne diseases, and chronic skin or soft-tissue infections. They are often selected when beta-lactam antibiotics are unsuitable or when there is suspicion of atypical pathogens.

Pharmacokinetics vary by compound. Doxycycline and minocycline are well absorbed orally and have long half-lives, enabling convenient dosing. Absorption of older tetracyclines is reduced by divalent cations (calcium, magnesium, iron), so they are advised to be taken on an empty stomach or separate from supplements. Tetracyclines can accumulate in bone and teeth, causing staining and growth effects in fetuses and young children; they are generally avoided during pregnancy and in children under eight.

Resistance to tetrasykliinien develops mainly via efflux pumps and ribosomal protection proteins (for example tet genes such as tet(M), tet(K), or tet(O)) and, less commonly, enzymatic inactivation. Adverse effects include GI upset, photosensitivity, esophageal irritation, and rarely liver or vestibular toxicity with long-term use.

History and derivatives: The tetracycline class emerged from soil actinomycetes in the mid-20th century, with the first tetracycline drugs followed by doxycycline and minocycline. Tigecycline, a glycylcycline, is closely related but considered distinct due to its modified structure.