Why should tetracyclines generally be avoided in children under 8 years old?

Tetracyclines should generally be avoided in children under 8 years old primarily because they can cause dental discoloration. This antibiotic class has the ability to bind to calcium ions, and when administered during the period of tooth development, it can lead to altered enamel formation. This results in permanent staining of the teeth, which typically appears as yellow, brown, or gray discoloration.

Children's teeth are particularly susceptible to this effect during the ages of 6 months to 8 years, a critical period for the development of both primary and permanent teeth. Consequently, healthcare providers generally recommend alternative antibiotics for this age group to prevent the adverse cosmetic effects associated with tetracyclines.