Doxycycline is an antibiotic in the tetracycline family of antibiotics, and has been in use since the 1960s. It is used for the treatment and prevention of a number of different infections. Of note, it is one of the few antibiotics for which there is a lot of experience in long-term use. For example, individuals are often prescribed doxycycline (or another tetracycline drug) for the treatment of acne, and they will often remain on this drug daily for months or even years. Additionally, doxycycline has long been used as a prevention drug for malaria, which involves taking it daily for the entire time one is at risk, which – for some people – involves many months.