Fluoroquinolone-Induced Achilles Tendon Damage: Structural and Biochemical Insights into Collagen Type I Alterations.

Fluoroquinolones, one of the most frequently used antibiotics, despite their wide spectrum of beneficial activity, are linked to serious adverse effects such as tendinopathies. Tendon injuries connected to the use of the group of drugs frequently affect the Achilles tendon-an anatomical structure, crucial to the proper mobility of lower limb, that is made of collagen fibers and extracellular matrix (ECM). Fluoroquinolones derive and decrease collagen and proteoglycans synthesis; they also disturb tendon regeneration by downregulating activity of metalloproteinases, enzymes essential for the proper collagen remodeling, especially after injuries. The exact way in which fluoroquinolones affect all these processes is not clearly known. However, some studies present that the chemical properties of fluorine such as electronegativity and ability to chelate di- and trivalent metal ions are one of the possible explanations for the problem. Our review summarizes various concepts of fluoroquinolones' impact on the Achilles tendon structure, particularly collagen type I. What is more, it emphasizes the risk factors for more frequent Achilles tendon damage and presents the potential preventive strategies associated with the usage of the antioxidants.