A 50-year-old man, nonalcoholic, with uncontrolled diabetes mellitus and hypertension was admitted to the hospital with history of high-grade fever and cough with scanty expectoration, of 2 days’ duration; and burning micturition and ulcer over left foot. Clinically the patient was febrile and diagnosed to have community-acquired left lower lobe pneumonia with urinary tract infection and cellulites of left foot.
Investigations revealed Hb was 10.4 g/dl, total leukocyte count was 9,500 cells/mm3 with neutrophilia, E.S.R. was 60 mm at one hour, random blood sugar was 250 mg/dl, blood urea was 25 mg/dl, serum creatinine was 1.3 mg/dl with normal creatinine clearance, and serum electrolytes were within normal limits. Peripheral smear for malarial parasite was negative. Urine microscopy showed 15-18 pus cells/high power field. However, urine culture was sterile and urine ketone bodies were negative. Blood and sputum culture did not grow any organisms. Final diagnosis of type 2 diabetes mellitus with hypertension with community-acquired pneumonia and urinary tract infection and cellulites of left foot with ulcer was made. In view of multiple infections, intravenous amoxicillin (1 g) and clavulanic acid (200 mg) every 8th hour were started and continued for 10 days. His general condition improved, and repeat chest x-ray showed resolution of pneumonia with better lung aeration. Cellulitis and urinary tract infection also showed improvement, and blood sugar and hypertension were under control. After 10 days, oral levofloxacin (500 mg/day) was started as a sequential therapy in view of persisting foot ulcer. On the third day of therapy, he became restless and speech became irrelevant and incoherent. Later he became abusive, violent and experienced visual hallucinations of people in his hospital room. Gradually his confusion worsened and he became more violent in nature. He slept very little. Psychiatric evaluation was suggestive of acute psychosis. The diagnosis of acute psychosis cannot be attributed to the clinical diagnosis as the patient had good improvement following 10 days of intravenous amoxicillin and clavulanic acid therapy. Other conditions like hypoglycemia, dyselectrolytemia, diabetic ketoacidosis, and meningitis were ruled out. Other drugs the patient was receiving were insulin, enalapril, atorvastatin, which are not known to result in such psychosis. So the likely possibility of levofloxacin-induced acute psychosis was considered and levofloxacin was stopped. Within 48 h of stopping levofloxacin, repeat psychiatric evaluation revealed him to be alert and oriented with no further hallucinations. His speech was normal in flow and content, and his concentration and recall were intact. He did not require any antipsychotic medications.