Nitrofurantoin, sold under the trade name Macrobid among others, is an antibiotic used to treat bladder infections. It is not effective for kidney infections. It is taken by mouth. Common side effects include nausea, loss of appetite, diarrhea, and headaches. Rarely numbness, lung problems, or liver problems may occur. It should not be used in people with kidney problems. While it looks like it is generally safe during pregnancy it should not be used near delivery. It works by slowing growth rather than killing bacteria. Nitrofurantoin was first sold in 1953. It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system. It is available as a generic medication. The wholesale cost in the developing world is 0.005 and 0.46 USD a dose. In the United States it is about 60 USD for 10 days of treatment.