A 68-year-old man on levofloxacin for community-acquired pneumonia presents after one week with atraumatic swelling of his Achilles tendon. Which statement about this adverse effect is correct?

• A It results from ischemic necrosis secondary to vasoconstriction
• B Fluoroquinolones increase the risk of tendinitis and tendon rupture, especially in elderly patients on corticosteroids ✓
• C The reaction is IgE mediated and responds promptly to antihistamines
• D Only first-generation fluoroquinolones carry this risk

Explanation

Fluoroquinolone class labeling includes tendinitis and tendon rupture, most often involving the Achilles tendon. Risk is highest in patients over 60 years, those receiving concurrent corticosteroids, and organ transplant recipients. The proposed mechanism involves fluoroquinolone-mediated oxidative damage to tenocyte mitochondrial DNA and matrix metalloproteinase activation, leading to collagen degradation. The reaction is not allergic, affects all generations of the class, and mandates immediate drug discontinuation and limb immobilization.

Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.