Posted by ed_uk on August 15, 2005, at 6:19:35
In reply to Paroxetine vs escitalopram, posted by ed_uk on August 15, 2005, at 5:51:25
Int Clin Psychopharmacol. 2005 May;20(3):131-7.
Prospective, multicentre, randomized, double-blind study of the efficacy of escitalopram versus citalopram in outpatient treatment of major depressive disorder.
Moore N, Verdoux H, Fantino B.
Departement de Pharmacologie, INSERM U657, Universite Victor Segalen, Bordeaux, France. nicholas.moore@pharmaco.u-bordeaux2.fr
Pre-clinical studies, active-control clinical trials and meta-analyses indicate that escitalopram (S-citalopram) might be more effective than citalopram, the racemic mixture of S- and R-citalopram. The present study aimed to confirm the superior efficacy of escitalopram over citalopram. A double-blind, randomized clinical trial was performed in which general practitioners and psychiatrists compared fixed doses of escitalopram (20 mg/day) with citalopram (40 mg/day) over 8 weeks in outpatients with major depressive disorder (MDD) [baseline Montgomery-Asberg Depression Rating Scale (MADRS) score > or =30]. Primary efficacy parameter was change from baseline to last assessment in the MADRS total score. Out of 138 (aged 44.1+/-10.9 years; initial MADRS score 36.3+/-4.8) and 142 (aged 46.2+/-11.1 years; initial MADRS score 35.7+/-4.4) evaluable patients who were randomized to escitalopram and citalopram, respectively, six and 15 withdrew prematurely (P=0.05). The MADRS score decreased more in the escitalopram than in the citalopram arm (-22.4+/-12.9 versus -20.3+/-12.7; P<0.05). There were more treatment responders with escitalopram (76.1%) than with citalopram (61.3%, P<0.01). Adjusted remitter rates were 56.1% and 43.6%, respectively (P<0.05). Tolerability was similar in both groups. This randomized double-blind trial confirms that escitalopram has a superior effect to citalopram in MDD.
.............................................................
What the **manufacturer** says.......................
Psychopharmacology (Berl). 2004 Jul;174(2):163-76.
Escitalopram versus citalopram: the surprising role of the R-enantiomer.Sanchez C, Bogeso KP, Ebert B, Reines EH, Braestrup C.
Research and Development, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby Copenhagen, Denmark. cs@lundbeck.com
RATIONALE: Citalopram is a racemate consisting of a 1:1 mixture of the R(-)- and S(+)-enantiomers. Non-clinical studies show that the serotonin reuptake inhibitory activity of citalopram is attributable to the S-enantiomer, escitalopram. A series of recent non-clinical and clinical studies comparing escitalopram and citalopram to placebo found that equivalent doses of these two drugs, i.e. containing the same amount of the S-enantiomer, showed better effect for escitalopram. These results suggested that the R-citalopram in citalopram inhibits the effect of the S-enantiomer. OBJECTIVE: To review the pharmacological and non-clinical literature that describes the inhibition of escitalopram by R-citalopram, as well as the implications of this inhibition for the clinical efficacy of escitalopram compared to citalopram. METHODS: The information in this review was gathered from published articles and abstracts. RESULTS: In appropriate neurochemical, functional, and behavioural non-clinical experiments, escitalopram shows greater efficacy and faster onset of action than comparable doses of citalopram. The lower efficacy of citalopram in these studies is apparently due to the inhibition of the effect of the S-enantiomer by the R-enantiomer, possibly via an allosteric interaction with the serotonin transporter. Data from randomised clinical trials consistently show better efficacy with escitalopram than with citalopram, including higher rates of response and remission, and faster time to symptom relief. CONCLUSION: The R-enantiomer present in citalopram counteracts the activity of the S-enantiomer, thereby providing a possible basis for the pharmacological and clinical differences observed between citalopram and escitalopram.
........................................................
The manufacturer claims that 10mg escitalopram is 'equivalent' to 40mg citalopram - I'm still not convinced about this. One would expect 10mg escitalopram to be 'equivalent' to 20mg citalopram. LOL, if R-citalopram really does reduce the efficacy of escitalopram, perhaps 10mg escitalopram is 'equivalent' to about 30mg citalopram.
............................................................................................................
Observations which are difficult to explain.............
1. Some babblers seem to find citalopram more 'sedating' than escitalopram
2. Some babblers seem to find escitalopram more anxiety-provoking that citalopram.Citalopram is a more potent H1 antagonist than escitalopram - but they're both very weak. I don't think this explains the above observations.
poster:ed_uk
thread:541835
URL: http://www.dr-bob.org/babble/20050811/msgs/541837.html