Tetracyclines (see table: tetracyclines) are bacteriostatic antibiotics that bind to the 30S ribosomal subunit, thereby inhibiting bacterial protein synthesis. Tetracyclines doxycycline minocycline tetracycline Pharmacology After oral administration is tetracycline to approximately 60-80%, doxycycline and minocycline are absorbed to ? 90%. But the absorption is by metallic cations (for example, aluminum, calcium, magnesium, iron.) Is lowered; Therefore, tetracyclines can not be taken together with preparations containing these substances (eg. as antacids, many vitamin and mineral supplements). Food intake lowers the absorption of tetracycline, but not of doxycycline or minocycline. Tetracycline penetrated in most body tissues and fluids. All accumulate in the uncongested bile. However, CSF levels are not reliable therapeutic. Minocycline is the only tetracycline, which achieves high concentrations in tears and saliva. Tetracycline and minocycline are primarily excreted in the urine. Doxycycline is excreted primarily in the intestinal tract. Indications tetracyclines are effective against infections caused by the following reasons: Rickettsia spirochetes (. Eg Treponema pallidum, Borrelia burgdorferi) Helicobacter pylori Vibrio sp Yersinia pestis Francisella tularensis Brucella sp Bacillus anthracis, Plasmodium vivax, Plasmodium falciparum Mycoplasma sp Chlamydia and Chlamydophila sp Some methicillin-resistant Staphylococcus aureus About 5-10% of pneumococcal strains, and many ?-hemolytic streptococci, many gram-negative rods uropathogenic bacteria and penicillinase-forming gonococci are resistant. Tetracyclines are interchangeable for most indications, although minocycline best aureus infections was studied in methicillin-resistant S.. Doxycycline is usually preferred for all of the following, because it is better tolerated and can be taken twice / day: infections caused by Rickettsia or Anaplasma, Chlamydia, Chlamydophila, Ehrlichia, Mycoplasma or Vibrio spp. Acute exacerbations of chronic bronchitis Lyme disease Brucellosis Anthrax Plague Tularemia granuloma inguinal syphilis prophylaxis for malaria caused by chloroquine-resistant P. falciparum Due to its high concentration in tears and saliva is the only Minozycklin Tetrazycklin, can eliminate the meningococcal in carriers and thus in this indication an alternative to rifampicin. Contraindications tetracyclines are contraindicated in patients who have had an allergic reaction to this, in patients with renal insufficiency (except doxycycline, where there is no dose adjustment for renal insufficiency) and in children <8 years (except sometimes in inhalational anthrax or other serious illnesses when the benefit outweighs the potential risk of tooth discoloration). Use during pregnancy and lactation tetracyclines are pregnancy category D (there is evidence of human risk, but clinical benefits may increase the risk outweigh). Tetracyclines cross the placenta, enter the fetal circulation one, accumulate in fetal bone and can - when used during the second or third trimester - cause permanent discoloration of the teeth. Hepatotoxicity may occur in pregnant women, especially after intravenous administration and in patients with azotemia or pyelonephritis. The intake of high doses during pregnancy can lead to fatty degeneration of the liver and be fatal. Tetracyclines enter into breast milk, but usually in small quantities (especially tetracycline). The use during lactation is generally discouraged. Side effects Side effects include GI disorders Clostridium difficile-induced diarrhea (pseudomembranous Kolitis- Clostridium difficile-induced diarrhea) candidiasis photosensitivity in children effects on bone and dental applications fatty liver Vestibular dysfunction (with minocycline) All oral tetracyclines provoke nausea, vomiting and diarrhea and can lead to a -C. (Pseudomembranous colitis) lead difficile-induced diarrhea and superinfection with Candida. If you are not swallowed with water, tetracyclines can cause esophageal erosions. Photosensitivity due to tetracyclines can manifest itself in a strong sunburn reaction. On the effects on bone and dental applications include staining of teeth, Zahnschmelzhypoplasie and abnormal bone growth in children <8 years and in fetuses. In infants tetracyclines may lead to idiopathic intracranial intracranial pressure and bulging fontanelle. Extremely high blood levels due to high doses or renal insufficiency can lead to fatal acute fatty liver degeneration, especially during pregnancy. Minocycline often leads to vestibular dysfunction, which leads to a limitation of its applicability. The use of minocycline is associated with the development of autoimmune diseases such as SLE and polyarthritis nodosa related, which may be reversible. Minocycline can also cause drug reaction with eosinophilia and systemic symptoms (DRESS), which are characterized by fever, rash, lymphadenopathy, hepatitis, atypical lymphocytosis, eosinophilia, and thrombocytopenia. Tetracyclines in patients with moderate to severe renal insufficiency cause azotemia or worse. Expired Tetrazycklintabletten can decay and result in taking a Fanconi syndrome. Patients should be instructed to destroy the expired drugs. Considerations dose doxycycline is excreted primarily in the intestinal tract and does not require dose reduction in renal failure. Tetracyclines may decrease the effectiveness of oral contraceptives and potentiate the effect of oral anticoagulants.

Health Life Media Team

Leave a Reply