A 28-year-old pregnant woman with a urinary tract infection is prescribed an antibiotic that chelates divalent cations and causes tooth discoloration. Which antibiotic is this?
- A Amoxicillin
- B Doxycycline ✓
- C Ciprofloxacin
- D Nitrofurantoin
Correct answer: B. Doxycycline
Explanation
Doxycycline, a tetracycline, chelates calcium in developing teeth and bones, causing permanent discoloration and is contraindicated in pregnancy. Ciprofloxacin causes cartilage damage, not tooth discoloration. Amoxicillin and nitrofurantoin are safe in pregnancy. Tetracyclines are avoided in all trimesters.
Reference: Katzung: Basic & Clinical Pharmacology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.