Amoxicillin (amox), also spelled amoxycillin, is an antibiotic useful for the treatment of a number of bacterial infections. It is the first line treatment for middle ear infections. It may also be used for strep throat, pneumonia, skin infections, and urinary tract infections among others. It is taken by mouth. Common side effects include nausea and rash. It may also increase the risk of yeast infections and, when used in combination with clavulanic acid, diarrhea. It should not be used in those who are allergic to penicillin. While usable in those with kidney problems, the dose may need to be decreased. Its use in pregnancy and breastfeeding does not appear to be harmful. Amoxicillin first became available in 1972. It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system. It is one of the most commonly prescribed antibiotics in children. Amoxicillin is available as a generic medication. It has a wholesale costs in the developing world of between 0.02 and 0.05 USD per pill. In the United States ten days of treatment costs about 16 USD.