Studies and Placebo

CloneX · 07-06-2005, 05:58 AM

When I look at studies about Paxil and other drugs, I really wonder how they come up with such placebo ratings - they seem so close to the non-placebo values:

http://www.rxlist.com/cgi/generic/parox_ad.htm

Headache on Paxil: 18%
Headache on Placebo: 17%

etc.

If you take a drug and have NO CLUE what side-effects you might experience, then how can those placebo values be that high - I mean, there are side-effects one usually wouldn't even think of.

In a double-blind study this shouldn't happen - but somehow I got the feeling they ask paxil-patients something like "What side-effects do you experience ?" while they ask placebo patients something like "Do you experience any side-effects...like headache, nausea, dizziness, ... ?"

Or they don't compare the intensity of those side-effects...

rdjanis · 07-06-2005, 08:49 AM

Interesting Clonex, I would say they would ask the placebo patients "do you experience any side effects... like headache etc......

scotty · 07-06-2005, 09:28 AM

Every symptom is supposed to be reported in a clinical trial. That's why you hear "menstrual pain" reported with drugs like Claritin for allergies. What's most significant in a trial is how the "symptoms" are labeled. In the case of paxil suicidal ideation got lumped into "emotional lability". In other words, it got buried within the terminology.

elisa · 07-06-2005, 09:57 AM

Clonex' post reminds me of the Tracy Johnson case who committed suicide when she was taken off Cymbalta and put on a placebo. She was thrown in withdrawl. Statistically, she didn't commit suicide on the drug.

The patients who were taking placebo and reported headaches could have been taken off the AD's suddenly and were going through withdrawl symptoms.

I also read some time ago about the fact that sedatives of some kind were given with some (all?) antidepressant trials. I can assume that the people on placebo were given these sedatives as well. (A double blind study would have to do that) Who knows if the side-effects were the result of these sedatives?

soulgalgirl · 07-06-2005, 10:25 AM

Something else I wonder, is how often do subjects get switched from drug to placebo and vice versa? I always thought the placebo group was the placebo group, and the drug group the drug group.

Clearly in the Cymbalta suicide, this was not the case. I think if subjects get switched from one group to another, it just confuses and invalidates the results of the whole test.

scotty · 07-06-2005, 10:58 AM

"I think if subjects get switched from one group to another, it just confuses and invalidates the results of the whole test."

And you win the prize for figuring out their motives!!! You can make a clinical trial show ANYTHING that you want!

07-06-2005, 05:58 AM	#1
CloneX Join Date: Oct 2003 Posts: 294	Studies and Placebo When I look at studies about Paxil and other drugs, I really wonder how they come up with such placebo ratings - they seem so close to the non-placebo values: http://www.rxlist.com/cgi/generic/parox_ad.htm Headache on Paxil: 18% Headache on Placebo: 17% etc. If you take a drug and have NO CLUE what side-effects you might experience, then how can those placebo values be that high - I mean, there are side-effects one usually wouldn't even think of. In a double-blind study this shouldn't happen - but somehow I got the feeling they ask paxil-patients something like "What side-effects do you experience ?" while they ask placebo patients something like "Do you experience any side-effects...like headache, nausea, dizziness, ... ?" Or they don't compare the intensity of those side-effects...

07-06-2005, 08:49 AM	#2
rdjanis "has a lavender scented keyboard" Join Date: Mar 2004 Location: Ontario Posts: 22,214	Re: Studies and Placebo Interesting Clonex, I would say they would ask the placebo patients "do you experience any side effects... like headache etc...... __________________ Rita

07-06-2005, 09:28 AM	#3
scotty Administrator Join Date: Feb 2004 Location: new jersey Posts: 46,995	Re: Studies and Placebo Every symptom is supposed to be reported in a clinical trial. That's why you hear "menstrual pain" reported with drugs like Claritin for allergies. What's most significant in a trial is how the "symptoms" are labeled. In the case of paxil suicidal ideation got lumped into "emotional lability". In other words, it got buried within the terminology. __________________ AKA Laurie "Faith is taking the first step even when you don't see the whole staircase." MLK

07-06-2005, 09:57 AM	#4
elisa Join Date: Jul 2004 Location: Ontario, Canada Posts: 11,473	Re: Studies and Placebo Clonex' post reminds me of the Tracy Johnson case who committed suicide when she was taken off Cymbalta and put on a placebo. She was thrown in withdrawl. Statistically, she didn't commit suicide on the drug. The patients who were taking placebo and reported headaches could have been taken off the AD's suddenly and were going through withdrawl symptoms. I also read some time ago about the fact that sedatives of some kind were given with some (all?) antidepressant trials. I can assume that the people on placebo were given these sedatives as well. (A double blind study would have to do that) Who knows if the side-effects were the result of these sedatives? __________________ On A/D's since 1995, switching due to side-effects on 30 different brands of TCA's, SSRI's, SNRI's, Antipsychotics, Benzo's & Imovane. 6 ECT's. Tapering from 225 mg Effexor XR May 17, 2004. (Equiv. to 60 mg Paxil) Last taper Effexor XR Jan 17, 2006 down to ZERO. Currently protracted withdrawal. Sept 2006: 25 mg Doxepin. March 13/09: 10 mg Desipramine

07-06-2005, 10:25 AM	#5
soulgalgirl Join Date: May 2005 Posts: 316	Re: Studies and Placebo Something else I wonder, is how often do subjects get switched from drug to placebo and vice versa? I always thought the placebo group was the placebo group, and the drug group the drug group. Clearly in the Cymbalta suicide, this was not the case. I think if subjects get switched from one group to another, it just confuses and invalidates the results of the whole test.

07-06-2005, 10:58 AM	#6
scotty Administrator Join Date: Feb 2004 Location: new jersey Posts: 46,995	Re: Studies and Placebo "I think if subjects get switched from one group to another, it just confuses and invalidates the results of the whole test." And you win the prize for figuring out their motives!!! You can make a clinical trial show ANYTHING that you want! __________________ AKA Laurie "Faith is taking the first step even when you don't see the whole staircase." MLK

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