This medication is used to treat a wide variety of bacterial infections, including those that cause acne. This medication is also used to prevent malaria. This medication is known as a tetracycline antibiotic. It works by stopping the growth of bacteria. This antibiotic treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections. Side Effects: Stomach upset, diarrhea, nausea, or vomiting may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.