Patients with psychiatry are often exposed drug-drug interactions, the main aim of the study is to investigate the drug interactions in the psychiatric patients. Most clinically significant drug interactions are pharmacodynamic (PD) and pharmacokinetic (PK) that results in augmented or antagonistic actions at a receptor. In metabolism, the major enzymes which are involved in drug interactions of psychotropic drugs are Cytochrome P450 (CYP) System. Drug-drug interactions are said to play a Significant and important role in the occurrence of adverse drug reactions. The major drug interactions in psychiatry are caused by haloperidol, clozapine, olanzapine, amitriptyline, amisulpride etc.. Concurrent use of these drugs can increase in QT prolongation and increase in the risk of Ventricular anthymias. The main aim of this study is to describe the drug interactions that causes major effects in psychiatric patients.

KEY WORDS: Olanzapine, haloperidol, amitryptaline, sertralin