Anti TB drug causing optic neuritis:

Ref: KDT 6th ed. pg. 742* Side effect of Ethambutol: Loss of visual acuity/colour vision, field defects due to optic neuritis is the most important dose and duration of therapy dependent toxicity.* Important side effects of antitubercular drugs:* Peripheral neuropathy (due to vit B6 deficiency): ISONIAZID* Orange color urine-RIFAMPICIN* Flu-like symptoms- RIFAMPICIN* Hyperuricemia/gout- PYRAZINAMIDE* Optic neuritis- ETHAMBUTOL* Nephrotoxic, Ototoxic, Neuromuscular Junction Blocker- STREPTOMYCINOther important points to remember about Anti TB drugs:* First line anti TB drugs are: HRZE (Isoniazid, Rifampicin, Pyrazinamide, Ethambutol)* All first line drugs are bactericidal EXCEPT- Ethambutol (it is bacteriostatic)* Most hepatotoxic ATT-Pyrazinamide* 1st line ATT with exclusive intracellular action-Pyrazinamide* 1st line ATT with exclusive extracellular action-Streptomycin* Which anti TB drugs are NOT hepatotoxic-Ethambutol and Streptomycin.* It should not be used in children below 6 years of age because these young patients may not be able to report visual impairment.