The concentration of a drug in the plasma, serum, or blood. In psychiatry, the term is most often applied to levels of lithium carbonate, tricyclic antidepressants, and anticonvulsants. Maximum clinical responses to these agents have been correlated with specific ranges of blood levels.
The concentration of a specific substance in the blood plasma or serum can be assessed through blood tests. These tests provide a means to measure the levels of various substances present in the bloodstream, offering valuable insights into an individual’s health and medical condition. By analyzing the concentration of these substances, healthcare professionals can diagnose and monitor various diseases, disorders, and overall physiological functions.