The document discusses therapeutic drug monitoring of lithium, which is used to treat acute mania and bipolar disorder. It outlines the optimal plasma concentration ranges for treatment of mania and prophylaxis based on 12-hour standardized lithium levels. Both dose-dependent and independent side effects are described. Factors that can impact lithium clearance like renal function and concomitant medications are also discussed. The document emphasizes the importance of therapeutic drug monitoring to ensure therapeutic concentrations are achieved while avoiding toxicity.