Which TB drug is commonly associated with bone marrow suppression and neuropathy as side effects?

• A. Isoniazid
• B. Linezolid
• C. Rifampin
• D. Ethambutol

Answer: (B)

Bone marrow suppression and neuropathy point to a drug with mitochondrial toxicity, which linezolid exhibits. Linezolid is used for drug-resistant TB and is well known for causing myelosuppression (especially thrombocytopenia) and peripheral neuropathy, particularly with longer courses. The underlying issue is that linezolid can impair mitochondrial protein synthesis in human cells, leading to reduced blood cell production and nerve dysfunction. Because of this, patients on prolonged therapy need regular blood counts and neurological checks. Other drugs listed have different common adverse effects—isoniazid can cause neuropathy mainly through vitamin B6 depletion and hepatotoxicity, rifampin tends toward hepatotoxicity and drug interactions, and ethambutol is mainly associated with optic neuritis.