My neice( 26 year old) is a case of Schizophrenia and has been recently diagnosed as suffering from Pulmonary TB. She was started with a 4 drug regime since last one month, which included isoniazid. Unfortunately her psychotic symptoms recurred after almost 3 years and she has become very depressed, irritable, aggresive and suicidical. my question is can Moxifloxacin be substituted for Isoniazid ? I am a doctor, a General Practiconer . I will be grateful if somebody can answer this question urgently