The use of tetracyclines during tooth development (last trimester of pregnancy, infancy and childhood) may cause permanent discoloration of teeth. Photosensitivity manifested by an exaggerated sunburn reaction has been observed in some individuals taking tetracyclines. As with other antibiotics, the use of doxycycline may result in overgrowth of nonsusceptible organisms including fungi.
Use in pregnancy & lactation: Results of animal studies show that tetracyclines cross the placenta and are found in fetal tissues and can have toxic effects on the developing fetus. Hence, the use of doxycycline in pregnancy is not recommended.
Use in children: Microdox is not recommended in children <12 years.