Adverse reactions such as vomiting, excessive intestinal gas and falling asleep at the breast have been reported in breastfed infants whose mothers were taking oral chloramphenicol. Milk concentrations are not sufficient to induce "gray baby" syndrome, but since chloramphenicol-induced aplastic anemia is not dose-related, this might occur, but has not been reported. An alternate drug is preferred to chloramphenicol during breastfeeding, especially while nursing a newborn or preterm infant. If the mother must receive chloramphenicol during nursing, monitor the infant for gastrointestinal disturbances and adequacy of nursing. Monitoring of the infant's complete blood count and differential is advisable. In some cases, discontinuation of breastfeeding might be preferred.