Studies have not been done in humans. Studies in mice, rats, and rabbits have shown that some sulfonamides cause birth defects, including cleft palate and bone problems. In addition, sulfa medicines may cause liver problems in newborn infants. Therefore, use is not recommended during pregnancy. Phenazopyridine has not been shown to cause birth defects in animal studies.
Sulfonamides pass into the breast milk.
This medicine is not recommended for use during breast-feeding. This medicine has been tested in a limited number of children 12 years of age or older. In effective doses, the medicine has not been shown to cause different side effects or problems in children than it does in adults. Severe skin problems and blood problems may be more likely to occur in the elderly. Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur.