Patented in 1957, Doxycycline is an antibiotic used in the treatment of infections caused by bacteria and certain parasites such as bacterial pneumonia, acne, chlamydia infections, early Lyme disease, cholera, typhus, and syphilis. It is also used to prevent malaria. Basically, Doxycycline treats infections by preventing the growth and spread of bacteria. Plus, it treats acne by killing the bacteria that infects pores, and also by decreasing a certain natural oily substance that causes it. Remember that you should take this medicine on an empty stomach, preferably at least 1 hour before or 2 hours after meals. As for its side effects, Doxycycline can cause diarrhea, nausea, vomiting, and an increased risk of sunburn. Remember that the use of this medication after the first trimester of pregnancy or in young children may result in permanent problems with the teeth including changes in their color. However, using Doxycycline during breastfeeding is probably safe.