What antibiotic can cause grey teeth in children?

Antibiotics That Cause Grey Teeth in Children

Tetracycline-class antibiotics, particularly older tetracyclines, can cause permanent grey-yellow-brown discoloration of teeth in children under 8 years of age. 1

Mechanism of Tooth Discoloration

Tetracycline antibiotics have the ability to bind calcium, which leads to incorporation into teeth, cartilage, and bone during calcification periods. This causes permanent discoloration of both primary and permanent dentitions.

• The discoloration occurs when tetracyclines are administered during tooth development (last half of pregnancy, infancy, and childhood to age 8 years) 1
• The color varies from yellow or gray to brown depending on:
  • Dose of the drug
  • Type of tetracycline used
  • Duration of treatment
  • Child's weight 2

Specific Tetracycline Antibiotics Associated with Tooth Discoloration

1. Tetracycline - The original drug in this class, associated with significant tooth staining
2. Doxycycline - Less likely to cause staining than older tetracyclines, but still carries risk
3. Minocycline - Can cause unique "black bones," "black or green roots," and blue-gray to gray darkening of permanent teeth 2
4. Tigecycline - A newer tetracycline derivative that may also cause yellow discoloration 3

Risk Factors and Timing

• Age of highest risk: Children under 8 years of age 1
• Critical period: During tooth crown formation 4
• Prevalence: Tetracycline and minocycline staining occurs in approximately 3-6% of cases 2
• Risk increases with: Multiple courses of tetracycline antibiotics 5

Clinical Considerations

Recent Evidence on Doxycycline

More recent studies suggest that limited, short-term use of doxycycline may have less impact on tooth discoloration:

• A 2013 retrospective cohort study showed that doxycycline used at recommended doses for short durations did not result in significant tooth staining in children 4
• The American Academy of Pediatrics and CDC now recommend doxycycline as treatment of choice for suspected tickborne rickettsial diseases in children of all ages, despite previous concerns about tooth staining 4

Important Exceptions and Alternatives

• For children under 8 years requiring antibiotics where tetracyclines would typically be indicated:
  • Erythromycin can be substituted (30-40 mg/kg divided over 3 doses for 3 weeks, then twice daily for 4-6 weeks) 4
  • Azithromycin is another alternative (5 mg/kg daily for up to 2 months) 4

Clinical Decision Algorithm

1. Is the patient under 8 years of age?

   • Yes → Avoid tetracycline-class antibiotics unless absolutely necessary
   • No → Tetracyclines can be used with minimal risk of tooth discoloration

2. Is the condition life-threatening (e.g., Rocky Mountain Spotted Fever)?

   • Yes → Use doxycycline regardless of age (benefit outweighs risk) 4
   • No → Use alternative antibiotics for children under 8

3. If tetracycline is absolutely necessary in children under 8:

   • Use doxycycline preferentially (less calcium binding than older tetracyclines)
   • Use the shortest effective course possible
   • Consider oxytetracycline if available (least likely to cause dental discoloration) 5

Important Caveats

• Permanent tooth discoloration is irreversible and may require cosmetic dental procedures later in life
• Even limited courses of tetracyclines in children under 6 years can lead to staining of permanent incisors 5
• The FDA label for tetracyclines explicitly warns against use in children under 8 years due to tooth discoloration risk 1
• Beyond age 8, the risk for tetracycline staining is minimal because visible tooth formation is largely complete 4