Phase I metabolism of drugs usually involves chemical processes such as hydroxylation, dealkylation and oxidation to the corresponding N-oxide or sulfoxides. Cytochromes (CYP1A2, CYP2B6, CYP2D6, CYP2C9, CYP2C19 and CYP3A4/5) are the pivotal isoenzymes involved in this metabolic event of most psychotropic drugs. A study proved that CYP1A2 is the primary isoform responsible for the metabolism of CPZ (mono and di-Ndemethylation (100%) and 5-sulfoxidation (64%) at 10 μM of CPZ. Molecular docking was performed with Flare TM V 8.0.0 from Cresset using CYP1A2 (2HI4) (Figure ). Metabolism prediction was also performed using BioTransformer 3.0 with CYP1A2, the enzyme most involved in the 2-CPTZ and CPZ metabolisms (supporting information). In addition, comprehensive studies to assess the inhibition capability of atypical antipsychotic drugs, including CPZ, levomepromazine, thioridazine, olanzapine, and risperidone in human liver microsomes have been reported. This study revealed that CPZ is the only antipsychotic drug that inhibited CYP1A2 activity with IC50 9.5 μM whilst levomepromazine and thioridazine (IC50 3.5-25.5 μM) inhibited CYP2D6, Olanzapine (IC50 14.65-42.20 μM) and risperidone (IC50 20.7 μM) selectively inhibited CYP3A-catalyzed midazolam 1' and 4'hydroxylation reaction.