A 68-year-old man with chronic kidney disease (eGFR 18 mL/min) requires a tetracycline for treatment of community-acquired atypical pneumonia. Which tetracycline can be given without dose adjustment because of its predominantly non-renal elimination?

• A Tetracycline
• B Oxytetracycline
• C Demeclocycline
• D Doxycycline ✓

Explanation

Doxycycline is unusual among tetracyclines in that it is largely cleared by non-renal routes: biliary secretion into the intestine and inactivation in the lumen by chelation. Fecal excretion accounts for most of its elimination, so no accumulation occurs in renal failure and no dose adjustment is needed. Older tetracyclines such as tetracycline and oxytetracycline are primarily renally excreted and accumulate in renal failure, where they worsen uremia through their antianabolic effect on protein synthesis.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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