Monitoring of tricyclic antidepressant plasma levels and clinical response: a review of the literature. Part II

Higher blood and brain concentrations of imipramine and desipramine seem not to impair anti-immobility effect in mice

We studied the relationship of blood and brain levels of imipramine (IMI) and/or its active metabolite desipramine (DMI) to behavioural response, in the tail suspension test (TST). Compared to the control group, doses of 3.75, 7.5, 15, 30 and 60 mg/kg of IMI given intraperitoneally reduced immobility scores significantly. There were significant negative correlations between doses, brain levels of IMI, DMI, IMI + DMI, blood levels of IMI, DMI, IMI + DMI and the animal behaviour. Higher level of IMI and its metabolite in brain and in blood did not impair anti-immobility effect. These findings agree with most results found in men treated with IMI, and suggest a linear or sigmoid relationship between the antidepressant concentrations and its biological response.

French summaries of product characteristics: content in relation to therapeutic monitoring of psychotropic drugs

The prescription information (summary of product characteristics, SPC) is compiled by the pharmaceutical industry as required by the national regulatory authorities. They vary in their content about the properties of drugs and about the usefulness of therapeutic drug monitoring (TDM) in the blood of patients. Based on a previous study carried out in Germany, the degree of agreement of French SPC for 59 psychotropic drugs with the existing medico-scientific evidence in the area of TDM was examined using a recently developed instrument. A summary score of SPC content (SPCC) related to TDM (SPCC(TDM)) has been calculated and compared with the level of recommendation of TDM of the AGNP-TDM expert group consensus guidelines for TDM in psychiatry [AGNP: Arbeitsgemeinschaft für Neuropsychopharmakologie und Pharmakopsychiatrie (Association for neuropsychopharmacology and pharmacopsychiatry)]. Among the antidepressants, antipsychotics, tranquillizers/hypnotic agents and mood stabilizers, the highest SPCC(TDM) scores in the French SPC were reached for imipramine (16), haloperidol (6), clonazepam (8) and lithium (23), respectively. Results were similar to those obtained from the analysis of German SPC, and considerable disagreement was found between the information on TDM in SPC and existing medico-scientific evidence, albeit less in the case of mood stabilizers. Taking into account the recommendations of the AGNP-TDM expert group guidelines, there is a deficit in the French SPC concerning TDM-relevant information. An amelioration of this situation could help to improve the clinical practice of TDM of psychotropic drugs, as the SPC is a widely used tool.