Why are tetracyclines contraindicated in pregnancy and children under 8?

• A. They can cause permanent tooth discoloration and enamel hypoplasia; photosensitivity.
• B. They are ineffective against dental bacteria.
• C. They commonly cause kidney failure.
• D. They require intravenous administration.

Answer: (A)

Tetracyclines are avoided in pregnancy and in children under 8 because they can become incorporated into developing teeth and bones. During tooth formation, these drugs strongly bind calcium and are deposited in the mineralizing tissues, leading to permanent tooth discoloration (often yellow-gray to brown) and enamel hypoplasia. Photosensitivity is an additional, well-recognized side effect. Since fetal teeth and the teeth of young children are still forming, exposure during these times can cause lasting changes in tooth color and enamel, which is why these drugs are contraindicated. Other options don’t capture this risk, as tetracyclines can be effective against bacteria and are not inherently linked to kidney failure or universal need for IV administration.