Vibramycine® (doxycycline) is a semi-synthetic tetracycline antibiotic discovered in the early 1960s in the USA (Pfizer). This drug is used for more than 60 years to treat or prevent bacterial infections. It is a first-line product to combat urinary, intestinal, genital or eyes infections. Doxycycline is active against both gram-negative and gram-positive bacteria. It is a synthetic derivative of oxytetracycline (α-6-deoxy-5-oxytetracycline), very stable in human serum. The active ingredient is commonly mixed with many different inert ingredients to formulate syrups, capsules or oral suspensions or tablets. The oral absorption of the drug is high. The mechanism of action implicates the binding of the drug substance to the 30S ribosomal subunit, thereby inducing inhibition of bacterial protein synthesis leading to bacteriostatic effects. It is active against a very broad range of bacteria, but cross resistance with other tetracyclines is common. Today, the drug remains largely prescribed to treat skin, respiratory and urinary tract infections. It is also an alternative drug, when penicillin is contraindicated, to treat sexually transmitted infections such as chlamydia, gonorrhea, and syphilis.
