Which antibiotic is notably avoided in developing teeth due to staining effects?

• A. Tetracycline
• B. Amoxicillin
• C. Clindamycin
• D. Cephalexin

Answer: (A)

Tetracycline can cause tooth staining because teeth developing in the fetus or in young children are still mineralizing. The drug binds strongly to calcium and gets incorporated into the forming dentin and enamel as a tetracycline–calcium complex. This becomes part of the tooth structure and, over time, shows up as intrinsic discoloration—usually yellow, brown, or gray—that can be permanent. Because of this staining effect, tetracycline is avoided during pregnancy and in children under about eight years old. Other antibiotics listed—amoxicillin, clindamycin, and cephalexin—do not share this mechanism and are not associated with the characteristic tooth discoloration seen with tetracycline.