Intravenous antidepressant treatment: focus on citalopram

During the last decade, the number of patients who consult primary care physicians or psychiatrists for symptoms of depression has doubled. The majority of depressed patients are prescribed oral medication; however, in several European countries antidepressant therapy may be initiated with a daily intravenous infusion. The choice of intravenous antidepressants was previously limited to agents such as dibenzepine, doxepin, clomipramine and viloxazine. More recently, the selective serotonin reuptake inhibitor (SSRI) citalopram has been administered as an intravenous infusion to severely depressed patients. The results from both open and double-blind clinical studies with intravenous citalopram suggest that it is an effective and well-tolerated treatment for depression. Moreover, when treatment is initiated by infusion and continued orally, citalopram is at least as effective as clomipramine, doxepin and viloxazine. As with oral treatment, adverse events experienced by patients are mild to moderate in severity with 50 % of patients reporting no adverse events. The high bioavailability of citalopram indicates that the switch from intravenous to oral citalopram would prevent a deterioration of symptoms as plasma drug concentrations would be maintained. Thus citalopram, the only SSRI available as an intravenous formulation, may be a useful addition for the treatment of severely depressed patients who may benefit from more intensive therapy. The aim of this paper is to review available data detailing the clinical outcome of intravenously administered citalopram in depressed patients.