How safe is doxycycline for young children or for pregnant or breastfeeding women?

Tetracycline antimicrobials entered into clinical usage in the late 1940s. Permanent dental staining from tetracyclines was first appreciated in 1956, eventually leading to avoidance of this class of antibiotics whenever possible in young children and pregnant or breastfeeding women. Doxycycline, introduced in 1967, binds calcium less avidly than prior tetracyclines and is regarded by some authorities as safe to prescribe for pregnant women and young children. Review of the available data, however, suggests that this interpretation may be incorrect or at least premature. In conclusion, until more definitive data are developed, doxycycline should continue to be only selectively prescribed for young children and pregnant or breastfeeding women for whom alternative, safer antibiotics are not available, and courses of treatment should be of as short a duration as possible.