Posted by ed_uk on October 10, 2004, at 13:00:25
In reply to Re: new to psychobabble, posted by Daniel Woodfield on October 10, 2004, at 9:42:00
Hello!
My mobile will be recharged later this evening so text me whenever you like. I will look forward to it. What are you studying in birmingham?Sorry if i confused you about escitalopram, this is how it is:
The drug citalopram(celexa, cipramil) consists of TWO chemicals, S-citalopram(escitalopram) and R-citalopram in a 50:50 ratio. eg. 20mg of citalopram consists of 10mg S-citalopram(escitalopram) and 10mg R-citalopram. S-citalopram is the mirror image of R-citalopram and so they are difficult to separate. Most, if not all of the activity of citalopram resides in the S-enantiomer: S-citalopram. As a result, the manufacturer has isolated S-citalopram(escitalopram) and sold it on its own under the brand names lexapro and cipralex.
So, the drug cipralex/lexapro consists of only ONE chemical, unlike cipramil/celexa.
In theory, 20mg of citalopram should have pretty much the same effect as 10mg of escitalopram/lexapro. From their clinical trials the manufacturer(lundbeck) claims that 10mg of lexapro/cipralex is equivalent to 40mg of citalopram(cipramil/celexa). In practice, I think this is dubious because 40mg of citalopram actually contains 20mg of escitalopram. In order for the manufacturers to be correct in their statement then R-citalopram must in some way inhibit the efficacy of escitalopram, I did see a study in a journal that suggested this was the case but it was not entirely convincing.
In the UK you will pay the same price for 28 citalopram 20mg as for 28 cipralex 10mg so it doesn't really matter which gets prescribed to be honest. Lundbeck, of course wants docs to prescribe cipralex because almost alll of the citalopram dispensed from uk pharmacies is generic( not the Cipramil brand made by lundbeck). So it's really in Lundbeck's interests to make everyone think that cipralex/lexapro is better than citalopram. When i worked in a pharmacy over the summer hols we never dispensed any cipramil- only generic citalopram. Never dispensed any seroxat/paxil or prozac either, it was ALWAYS the generics- basically every other prescription had fluoxetine on it!! A drug rep came from lundbeck to try and convince us that cipralex was the best ssri, to be honest though the only thing that did surprise me was that lundbeck is selling cipralex in the uk at the same price as generic citalopram ( ie. each 10mg cipralex is the same price as a 20mg citalopram tablet). I doubt this applies in other countries though but i could be wrong! Anyway i hope i haven't bored you about cipralex!Here is that study i was talking about, animal studies never were that helpful though because you never know whether what happened in a rat would happen in a human!
Pharmacol Biochem Behav. 2003 Jul;75(4):903-7. Related Articles, Links
R-citalopram counteracts the effect of escitalopram in a rat conditioned fear stress model of anxiety.Sanchez C, Gruca P, Bien E, Papp M.
Neuropharmacological Research, H. Lundbeck A/S, Copenhagen-Valby, Denmark. cs@lundbeck.com
LOOK WHO DID THE STUDY!!
S-citalopram (escitalopram) mediates the serotonin reuptake inhibitory effect of the racemate, R,S-citalopram (NORMALLY JUST CALLED CITALOPRAM). The effect of escitalopram (0.5-3.9 mg/kg) was investigated in a rat conditioned fear stress model of anxiety and compared to the effects of R-citalopram (1.0-7.8 mg/kg), R,S-citalopram (4.0 and 8.0 mg/kg), and escitalopram (2.0 mg/kg)+R-citalopram (7.8 mg/kg). Diazepam (0.95 mg/kg) and buspirone (4.6 mg/kg) were included as positive controls. During an acquisition session, rats were allowed to freely explore a novel cage for 9 min. During that time, they received two inescapable footshocks through an electrifiable grid floor. Groups of nonshocked control rats were run in parallel. During an expression session on the next day, rats were treated with drug or vehicle 30 min before they were reintroduced into the test cage for a 9-min period this time without receiving footshocks and the total distance travelled was recorded. The distance travelled by vehicle-treated rats was markedly suppressed compared to a vehicle-treated group of nonshocked controls. Escitalopram produced a dose-dependent inhibition of the conditioned suppression of exploratory behaviour (minimal effective dose 1.0 mg/kg). Interestingly R,S-citalopram 4.0 and 8.0 mg/kg produced significantly smaller effect than escitalopram 2.0 and 4.0 mg/kg, receptively. R-citalopram, 7.8 mg/kg, produced a significant effect. However, in spite of this, R-citalopram (7.8 mg/kg) significantly inhibited the effect of escitalopram (2.0 mg/kg). The activity in drug-treated nonshocked groups was similar to the vehicle-treated group, except for the buspirone-treated group where a significant reduction was observed. The finding that R-citalopram inhibits the effect of escitalopram may be relevant to the improved clinical efficacy seen with escitalopram compared to R,S-citalopram in the treatment of anxiety and depression.So who knows? Maybe cipralex really is better for anxiety but ther is little reason to think that it would have less side effects than citalopram- as the rep tried to encourage us. Perhaps R-citalopram does contribute to the side effects of cipramil/celexa but if S-citalopram is the potent SSRI this seems unlikely.
Ed
poster:ed_uk
thread:400810
URL: http://www.dr-bob.org/babble/20041007/msgs/401192.html