Abstract
In general, plasma level monitoring and pharmacokinetics are widely studied and have been successfully applied in the field of epileptic therapy. Before similar monitoring can be used with psychiatric drugs the possible problems of obtaining samples from the type of patient who receives this therapy should be considered. Patients who receive chlorpromazine sometimes show plasma levels lower than the recommended range, even though their symptoms are considered controlled. Correct interpretation of plasma level results depends on an understanding of the factors responsible for these low plasma levels.