Efficacy of intravenous citalopram compared with oral citalopram for severe depression: Safety and efficacy data from a double-blind, double-dummy trial

Background: Intravenous administration is often beneficial in the treatment of severely depressed patients. It is mainly the tri- and tetracyclic antidepressant drugs that can be administered intravenously. However, these drugs have a less favourable safety profile than newer antidepressants, such as the selective serotonin reuptake inhibitors (SSRIs). Citalopram is the only SSRI that is available in a formulation for infusion. This double-blind, randomised, multicentre trial was designed to compare the efficacy and tolerability of citalopram infusion (40 mg per day) and citalopram tablet (40 mg per day). Methods: Patients were randomised to receive either placebo tablet plus citalopram infusion (the infusion group; n=135) or citalopram tablet plus placebo infusion (the tablet group; n=119). After receiving randomised treatment for eight days, all patients entered an open treatment phase, during which they received oral citalopram 40 mg per day for five weeks. Results: Although there was no difference in Montgomery–Åsberg Depression Rating Scale (MADRS) scores at the end of the randomised treatment period, by the end of the open treatment phase the reduction in MADRS scores was significantly greater in the infusion group than in the tablet group (p=0.015). The infusion group also showed superior efficacy in Clinical Global Impressions assessments. Citalopram was equally well tolerated in both treatment groups. Conclusions: This trial confirmed the efficacy of citalopram 40 mg per day, and clearly supports the use of citalopram infusion in the treatment of severely depressed, hospitalised patients.