Questions Regarding Mayo Clinic Study Re-Posted to YouTube

I have re-posted my comments and questions regarding the Mayo Clinic video on YouTube.

Questions Regarding Mayo Clinic Study Deleted from YouTube Video Post

My friend Bob, who has a terrific blog called Parkinson's Patients: Yes We Can Dance, recently drew my attention to a Mayo Clinic video on YouTube. In it, a physician named J. Michael Bostwick tells us that according to the findings of his recent study, at least one in every five people with Parkinson's who takes a dopamine agonist will experience compulsive behavior as a side effect.

That number is radically higher than any previous estimate, and given that even the lower numbers are completely unsupported by the evidence presented in any of the other papers I've ever read, i was curious. i read the study, something that, in general, i HIGHLY recommend to anyone with Parkinson's who is trying to make treatment-related decisions.

As I expected, there were some very curious aspects of this study, and a day or two ago I posted my observations, questions and criticisms of this study as comments to the YouTube video.

Today, I checked in on the video to find that my comments have been deleted.

So, I'm posting them below. I am planning a more comprehensive critique of the study, but wanted to get these comments back up on the Internet just in case anyone reads my newest post on theYouTube video post, which directs them here, before that comment is deleted, too. Here they are:

(I realize, reading these six items again today, that they probably won't make sense to anyone who hasn't read the study. However, I do want them available while I work on a post that will provide more explanation, so that it is clear that comments, criticisms, and questions that were deleted from the Mayo Clinic video post were rational, logical and posed in a civilized fashion.)

1) I beg everyone who sees this to read the actual study - not just the abstract, the whole study – it can be found here: http://www.ncbi.nlm.nih.gov/pmc/issues/177782/ - just scroll down a little – the pramipexole (Mirapex) package insert can be found here: http://www.accessdata.fda.gov/Scripts/cder/DrugsatFDA/index.cfm?fuseaction=Search.Label_ApprovalHistory - check my facts, please!!

2) For 4 out of 7 patients, there is no stated temporal relationship btw initiation/increase or cessation/decrease in dopamine agonists & certain behavior – in the absence of a temporal relationship, on what basis are you claiming the existence of an association between the drug and the behavior?

3) 2 out of those 4, in addition to having no stated temporal relationship, are footnoted as “not clearly pathologic” – well, you cant’ have your cake and eat it too – if they aren’t pathologic, then they are not eligible for inclusion in a study with pathological as an inclusion criterion

4) you define 2mg/day or greater as therapeutic dosage of pramipexole – but according to the package insert, “doses of 3 mg, 4.5 mg, and 6 mg per day of MIRAPEX tablets were not shown to provide any significant benefit beyond that achieved at a daily dose of 1.5 mg/day.” So, actually, less than 2mg/day is definitely therapeutic.

5) You exclude 28 of the 66 people taking agonists on the basis of this never before heard and according to the package insert completely erroneous categorization of their agonist dosage as subtherapeutic.

6) If you remove the patients who were included without any basis for inclusion, and include those who were excluded without any basis for exclusion, you get 3 patients out of 66 taking dopamine agonists who experienced compulsive behavior, which indicates a prevalence of 4.5%, or approximately ¼ that which you are claiming to have found.

*Is* dopamine agonist therapy associated with pathological gambling?

Well, folks, I finally have corroboration from a doctor, published in a peer-reviewed journal (not that I think that means much, but others might) for my assertion that none of the gambling studies to date (which means as of 2007, or early 2008 at the latest), demonstrates the extent of risk of development of pathological gambling when taking dopaminergic meds. Dr. Zand says:

"Thus far, published reports have been able to neither demonstrate the extent of risk for gambling-related problems nor study the correlation of dosage with this potential adverse effect among Parkinson’s disease patients treated with dopaminergic medications."

My absolute favorite bit is this, with reference to the 2005 study by Dodd, et. al.:

"This report, however, did not include the total number of patients exposed to pramipexole, ropinirole or other dopamine agonist agents, so the incidence of pathological gambling could not be estimated."

Which is exactly what i said in my May, 5, 2008 blog entry Pathological Gambling Caused by Drugs Used to Treat Parkinson’s Disease: Yet Another Closer Look, Part Two, albeit not nearly so concisely.

I wonder why this paper didn't get any press whatsoever?

Zand R. Is dopamine agonist therapy associated with developing pathological gambling in Parkinson's disease patients? Eur Neurol. 2008;59(3-4):183-6. Epub 2008 Jan 29.