General Principles of Pharmacologic Therapy

The use of psychotropic drugs in clinical psychiatry began in the late nineteenth century, changing the goal of treatment of mental illness from symptom improvement to social functioning. Psychotropic drugs are still widely used today. Clinicians prescribe the right drug, in the right dose, and in the right manner to the right patient population to lead them to recovery. This goal requires a proper patient-provider relationship, accurate diagnosis, and appropriate drug selection. Understanding the effects and side effects of drug administration requires knowledge of adherence, pharmacokinetics, pharmacodynamics, and pharmacogenomics. Pharmacokinetics is affected by processes such as drug administration, absorption, distribution, metabolism, and exertion, and is colored by environmental and genetic factors such as aging, comorbidities, and concomitant use of other drugs. Knowledge of these factors is necessary. In order to establish an appropriate patient-provider relationship, it is necessary to understand the concept of evidence-based treatment planning and shared decision making (SDM) when making treatment decisions with patients. Finally, after drug administration, evaluation and monitoring of efficacy, adverse drug reaction, and side effects are necessary. This chapter aims to summarize the basic knowledge required for effective pharmacotherapy, which will ultimately contribute to effective and safe pharmacotherapy.