Plasma Levels of Imipramine and Desmethylimipramine during Therapy

Individual variations in drug metabolism are important factors affecting both toxicity and clinical effectiveness (Brodie, 1964; Kalow, 1965; Price Evans, 1965). In most cases the best available index of the drug concentration at the site of action is the plasma level. An estimate of this will show whether the optimal concentration is present and in some cases may indicate whether new symptoms can be attributed to toxic side reactions.