Note: The following Health Initiative announcement was written in collaboration with The Chion Foundation (chionfoundation.org).
While originally identified as a key immunological molecule in the allergic response of humans, histamine is actually an evolutionarily-primitive molecule that plays many fundamental roles across many animal phyla. Humans possess four histamine receptor subtypes: histamine 1 receptor (H1R) through the histamine 4 receptor (H4R). The H3R drew our attention because it appears to achieve its homeostatic function via regulation of the release of various neurotransmitters including serotonin, acetylcholine, and dopamine.
If H3R were a critical receptor in the pathophysiology of Prader-Willi Syndrome (PWS), this would explain why it has, to date, been difficult to identify a satisfying single genetic cause for PWS. While the role of the H3R has not yet been studied in PWS, research has revealed dysfunction in neurotransmission in patients with PWS. Specifically, the serotonergic system and, possibly the dopamine system, appear to be compromised in individuals with PWS. Dopamine is also known to play an important role in feeding and satiety. We note that the neurotransmitters that are dysregulated in individuals with PWS are those that are regulated by the H3R.
While improved wakefulness alone would be a major improvement in the quality of life of individuals with PWS, there are many reasons to believe that the neurologic benefits of pitolisant in the PWS population might extend beyond improving wakefulness. For example, many individuals with PWS struggle with mental health issues and learning disabilities which could potentially be improved by pitolisant. Moreover, research suggests that the cognitive enhancing activities of drugs such as pitolisant may help protect against schizophrenia, attention deficit disorder, and other cognitive disorders. Lastly, children with PWS are often plagued with severe gastrointestinal problems that remain difficult to treat. Pitolisant may affect multiple cells in the gastrointestinal tract and could theoretically improve these symptoms. For these reasons, we propose that it is biologically plausible that pitolisant would be useful for the PWS patient population, not only in the treatment of excessive daytime sleepiness, but that it could also improve the ability of individuals with the syndrome to respond to environmental stressors such as changes in temperature, high glucose loads, and complex social interactions.
While pitolisant is currently only available in Europe, the Chion Foundation and TREND Community are working with the US Food and Drug Administration (FDA) to help individuals personally import pitolisant from Europe based upon the FDA’s discretion (www.fda.gov/ForIndustry/ImportProgram/ImportBasics/ucm432661.htm). Participants will be invited to document their experience with pitolisant on TREND Research.
If you would like to participate in The Pitolisant Initiative or have questions, please contact us: firstname.lastname@example.org.