Bacterial pneumonia can increase serum concentration of clozapine

Concentrations of serum clozapine, c-reactive protein (CRP) and alpha1 acid glycoprotein were greatly increased during a bacterial pneumonia in a 53-year-old woman. As the pneumonia subsided, and CRP and alpha1 acid glycoprotein normalised, serum clozapine concentration also decreased to the previous level. An increased serum clozapine and a lowered N-desmethylclozapine to clozapine ratio during the infection suggest a decreased cytochrome P 450 (CYP)1A2 activity. Cytokine-mediated CYP1A2 suppression is discussed.