Posted by dr dave on September 1, 2002, at 8:46:58
In reply to Re: Lexapro side-effects » dr dave, posted by pharmrep on August 31, 2002, at 22:13:49
I'll try to explain this again. Lexapro 10mg contains 10mg of s-citalopram. Celexa 20mg contains 10mg of s-citalopram plus 10mg of r-citalopram. They both have the same amount of active ingredient and differ only in the presence or absence of r-citalopram. The value of removing r-citalopram is the issue under discussion here. You have to compare like with like to get meaningful results. If you want to find out whether r-citalopram affects the efficacy of s-citalopram, you have to look at the same amount of s-citalopram with or without the r-citalopram. This is to be sure any differences seen are due to the r-citalopram, and not due to diifering doses of s-citalopram.
You cannot compare side-effects from Lexapro 10mg with those from Celexa 20mg in these study populations because there are no figures for Celexa 20mg. Rates reported in other studies are not directly comparable because they occurred in a different population and may have been measured differently. So the only figures you can properly compare to have any hope of accuracy are the figures I have given, which show no significant difference between Lexapro and Celexa.
As you have brought up the FDA, it is worth repeating that they have concluded Lexapro is not significantly better than Celexa. This is all that I am saying. Are they not objective? Are the other independent authorities which have reviewed this research not objective? There is a very serious debate to be had here, and I repeat that I think it should be the content and quality of the evidence which should be our focus.
> > It is repeatedly claimed Lexapro has fewer side-effects than Celexa. What does the data show? In the Burke et al trial 85.6% of those on Lexapro 20mg had side-effects compared to 86.4% on Celexa 40mg (not statistically significant). Not impressive, I would suggest. 10.4% of those on Lexapro 20mg discontinued because of side-effects compared to 8.8% of those on Celexa. So in fact more discontinued Lexapro than Celexa. But the result is not statistically significant and therefore likely to be a chance result.
> >
> > The incidence of discontinuations on Lexapro 10mg a day was 4.2% compared to 2.5% on placebo. Again, not statistically significant. The overall rate of side-effects on Lexapro 10mg was 79.0% compared to 70.5% on placebo (not statistically significant). The comparison between Celexa 20 mg and placebo is not available as this dose was not used.
> >
> > So the Burke study provides no data to support the claim that Lexapro has fewer side-effects than Celexa.
> >
> > Gorman gives discontinuation rates for Lexapro in both doses as being 5.9% versus 2.2% for placebo (not statistically significant). No equivalent rate for Celexa is available. No more detail on side-effects is given in this, the most comprehensive analysis of the data currently available. Myself, I ask why not, if this is such a step forward in terms of side-effects.
> >
> > These results are entirely consistent with the hypothesis that there is no statistically significant difference in side-effects between Lexapro and Celexa, and provide no evidence of the difference that is so widely claimed as being an established fact.
> >
> > If there is other evidence to fit into this overall picture, this must be considered, but these results seem to suggest very powerfully that there is no significant difference in side-effects.
> >
> > Decide for yourself on the basis of actual hard facts.
>
> ** Ok Dr. Dave...I will ask again. Why are you comparing the higher 20mg of Lexapro to 40mg of Celexa when its 10mg of Lexapro that should be your comparing point? Do you normally start your patients at the highest dose? You should compare 10mg Lexapro to 40mg of Celexa since that is where the studies show that "10mg of Lexapro is at least as effective as 40mg of Celexa" Of course if you look at the 20mg of Lex then you will see higher side effects than the 10mg. But as you said...not a statistically significant difference than placebo. That is a good thing, so why the complaint...the FDA even allows the statement in the package insert. Maybe it would have been easier for you if Forest just compared Lexapro to Placebo like most new drugs that come out. Since Celexa and placebo are in the comparison, and Lexapro does show a significant statistical difference ahead of both...you seem to think there isnt. Stop trying to find a reason why you disagree with the studies...and be a little more objective, or better yet...let the folks here in the US have the chance to decide for themselves if they want to try Lexapro...since you arent willing to and have had the chance for some time now.
poster:dr dave
thread:109458
URL: http://www.dr-bob.org/babble/20020829/msgs/118413.html