Involvement of cytochromes p450 in drug-drug interactions: an overview

Drug interactions can cause iatrogenic disease. If concurrent medications are taken, the potential exists for a drug interaction to occur. Renewed interest in the topic interactions has been generated by the fatal interactions involving non-sedating histamine H-1 antagonists and the recent intriduction of two therapeutic agents, the selective serotonin reuptake inhibitors (SSRIs) and HIV protease inhibitors, for the treatment of depression and AIDS, respectively. These three therapeutic agents have been implicated in clinically significant drug interactions. The consequences of these interactions vary in clinical significance, extent, and effect. Some interactions are theoretical whereas others may lead to severe iatrogenic adverse experiences including lethal consequences.The purpose of this review is to alert the medical practioner to potential drug interactions that may occur when these drugs are prescribed to patients. The pharmacological basis and clinical signficance of these interactions are reviewed. The pharmacological mechanisms underlying these interactions are illustrative of those that may be involved for many other medications. Doctors should be aware of the potential pitfall that may occur when certain groups of drugs are prescribed with concurrent medications.