[Coadministration benzodiazepine and antidepressant drugs: the state of art]

The potential for drug-drug interactions in psychiatric patients is very high as combination psychopharmacotherapy used to treat comorbid psychiatric disorders, to treat the adverse effects of a medication, to augment a medication effect or to treat concomitant medical illnesses, etc. Interactions can be pharmacodynamic or pharmacokinetic in nature. In clinical practice the benzodiazepines (BZD) are often prescribed together with antidepressant drugs for the treatment of depression. Although there has been no convincing evidence to show that such a combination is more effective than antidepressants alone and no clear indication for the use of this combination. Yet, anxiety frequently coexists with depression, and an anxiolytic is often added. But, it is BZD which are systematically prescribed together with antidepressants. However, BZD themselves have no antidepressive effects and we lack firm evidence for or against this combination therapy. We are focused on the pharmacodynamic interactions between anxiolytic such as BZD, and antidepressant drugs which may resulting in a reduction of the effects of one of the drugs. It is known that BZD decrease the serotoninergic transmission. Also, it may be suggested that combined BZD-specific serotonin reuptake inhibitors, should be avoided. This paper reviews, in vitro and in vivo and particularly in clinical, the evidences for drug interactions between BZD and antidepressant drugs. In clinical, all trials that compared antidepressant-benzodiazepine treatment with antidepressant alone for adult patients with major depression were sought by electronic searches of Medline and several other databases (1970 to 2005), combined with hand searching, reference searching and SciSearch.