Nitrofurantoin can pass into breast milk and may harm a nursing baby. You should not breast-feed while you are taking this medicine. Nitrofurantoin should not be given to a child younger than 1 month old. Nitrofurantoin comes as a capsule and a liquid to take by mouth. Nitrofurantoin usually is taken two or four times a day for at least 7 days. Take it with a full glass of water and with meals. Macrobid is the brand name for nitrofurantoin, an antibiotic used to treat or prevent urinary tract infections. Macrobid works by killing the bacteria that cause the infection or by preventing the. The usual dose of nitrofurantoin to treat a urinary tract infection is either 100mg taken twice a day or 50mg taken 4 times a day. Severe infections may need a higher dose of 100mg taken 4 times a day. Learn about Macrobid (Nitrofurantoin) may treat, uses, dosage, side effects, drug interactions, warnings, patient labeling, reviews, and related medications. 'Nitrofurantoin for Urine Infections. Water Infection Symptoms and Treatment' discusses Nitrofurantoin as a treatment of UTI. Pictures of Macrobid (Nitrofurantoin), drug imprint information, side effects for the patient. 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. Nitrofurantoin oral capsule is available as both generic and brand-name drugs. Brand-names: Macrobid and Macrodantin. Nitrofurantoin is also available in an oral suspension. All forms of nitrofurantoin are contraindicated in neonates 1 month old. Nitrofurantoin can induce hemolytic anemia in G6PD-deficient patients and in patients whose RBCs lack sufficient quantities of reduced glutathione, including neonates.