CYP1A2 and Hyperglycemia: Co-administration of clozapine and fluvoxamine, the potent inhibitor of CYP1A2 and CYP3A450, has been reported to result in reduction of norclozapine concentrations and as a consequence a decrease in the incidence of weight gain, hyperglycaemia, hypertriglyceridaemia, supporting norclozapine contribution to the development of metabolic side-effects46.