Linezolid inhibits protein synthesis by binding to the 50S ribosomal subunit at a unique site. Its most serious dose-limiting adverse effect with prolonged use (>2 weeks) is:

• A Nephrotoxicity due to tubular accumulation
• B Myelosuppression, particularly thrombocytopenia ✓
• C Peripheral neuropathy due to mitochondrial toxicity
• D Pseudomembranous colitis

Explanation

Linezolid's most clinically significant dose-limiting adverse effect with prolonged therapy is myelosuppression, manifesting most commonly as thrombocytopenia, but also anemia and neutropenia. This occurs due to inhibition of mitochondrial protein synthesis in bone marrow precursors. Peripheral neuropathy and optic neuropathy can also occur with very prolonged use but thrombocytopenia appears earlier and more consistently. Weekly CBC monitoring is recommended.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.