Safety and efficacy of oral escitalopram as continuation treatment of intravenous citalopram, in patients with major depressive disorder - The Navigade Switch study

Intravenous (iv) administration of an antidepressant is a common practice in some European countries, particularly in France, Spain, and Italy in the initial treatment phase of hospitalised, severe depressed patients. After a beneficial response is observed, patients are switched to an oral formulation. The approved treatment period of the iv form of citalopram is limited to 8-10 days. The high bioavailability of citalopram permits the use of identical iv and oral doses. Citalopram is a racemate, consisting of a 1:1 mixture of the S- and R-enantiomers. The therapeutically active component is the S-enantiomer (escitalopram). Pharmacokinetic single dose administration studies in healthy subjects have demonstrated that daily oral administration of 20 mg of escitalopram or 40 mg citalopram results in similar plasma concentrations of the S-enantiomer of citalopram. This open-label multicentre French prospective study investigated the tolerability and efficacy of oral escitalopram 10 and 20 mg/day, administered for a 6-week period as continuation treatment of citalopram (20 mg or 40 mg daily) intravenous (iv), in patients with Major Depressive Disorder. A total of 171 patients were enrolled, of whom 147 (85 %) completed the study. The mean MADRS score at inclusion (last citalopram dose) was 31.6 +/- 9.9. The total MADRS score decreased after 3 days of oral treatment with escitalopram. Escitalopram demonstrated a continuous effect in treating depressive symptoms throughout the study. The decrease in MADRS mean total score from baseline was statistically significant to each visit (day 3, 15;p < 0.0001). At final visit (J42), the decrease was - 18.9 +/- 11.7 (p < 0.0001) and the MADRS mean total score was 12.7 +/- 9.3. There were no differences seen in the patient response comparing gender, age, and the single or recurrent episodes. The changes of Clinical Global Impression scores (CGI-S, CGI-I, PGE-Patient Global Evaluation) were also indicative of an improvement of the patients' depression. The CGI-I and PGE scores were significantly correlated indicating good agreement between investigator and patient in rating the degree of improvement. At the end of the study, 67 % of patients were classified as responders (decrease of MADRS score from baseline > 50 %), and the majority of them were considered remitters (final MADRS score <= 12). Overall; the switch from intravenous citalopram to oral escitalopram was well tolerated in the study population. In all, 57 patients (33 %) reported at least one adverse event (AE) during the study (21 patients in the 10 mg group and 36 patients in the 20 mg group); of these, 7 patients (4 %) withdrew from the study. The most frequently reported AEs were suggestive of residual symptoms of depression (anxiety, 9 %;insomnia, 5 % of patients). In conclusion, in this study oral escitalopram (10 mg or 20 mg) was well tolerated as continuation treatment after switching from intravenous citalopram (20 mg or 40 mg). From the efficacy and safety data of this study, it can be concluded that the switch from citalopram iv to oral escitalopram (10 and 20 mg/day) is effective in decreasing depressive symptoms, and could be safely proposed in patients with major depressive disorder.