Doxycycline

Doxycycline (alpha-6-deoxytetracycline) has the empirical formulas C₂₂H₂₄N₂O₈·HCl and ½ [C₂H₅OH·H₂O] and molecular weight 512.9. Doxycycline is a second-generation tetracycline with increased oral bioavailability and tissue penetration as a result of its improved lipophilicity compared with earlier tetracyclines. Its mechanism of action is inhibition of microbial protein synthesis through interaction with 30S ribosomal subunits. It is almost universally administered orally and has a prolonged serum half-life. It is available as both doxycycline monohydrate and doxycycline hyclate. Tradenames include Vibramycin, Doryx, Doxy-100, Doxsig, Zadorin, Doxylag, Periostat, and Doxycin (Figure 68.1). Figure 68.1 Chemical structure of doxycycline. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315152110/08d8042d-9481-4a8d-8c27-9bd589f6de6b/content/fig68_1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>