<s>[INST] Mamuna aged 16yrs has infective psychosis and has been on ciprofloxacin 500mg 12hrly for about 4 weeks. The widal titres have however remained high - s. typhi o 1:320 and s. typhi H 1;160. He has been re-admitted and my question is how best do we treat her? [/INST] Hello Mamuna!I would recommend switching to another antibiotic, probably doxycycline combined with Ceftriaxone. Regarding the psychosis, an anti-psychotic like olanzapine could be helpful!A new brain MRI is also necessary. Hope you will find this answer helpful!Best wishes, Dr. Aida </s>