Which of the following is NOT a known side effect of tetracyclines?

• A. PTC
• B. Bone growth retardation
• C. Pigmented cysts of the conjunctiva
• D. Whorl Keratopathy

Answer: (D)

Tetracyclines have several well-documented adverse effects beyond the common GI upset. They can be associated with intracranial hypertension (pseudotumor cerebri), especially with doxycycline and minocycline, and this can present as headaches and papilledema. They can also affect developing bones and teeth, leading to growth retardation and permanent teeth staining if given during tooth development. Long-term minocycline use has been linked to pigmented ocular changes, including pigmented conjunctival cysts. In contrast, whorl keratopathy, or vortex keratopathy, is a corneal finding classic for drugs like chloroquine or hydroxychloroquine (and other unrelated agents such as amiodarone), not tetracyclines. So the option describing Whorl Keratopathy is not a known side effect of tetracyclines.