Now that we know oxytocin has helped my son decrease his weight and hyperphagia, we have to figure out how to maintain its effectiveness over time. As I shared in my last post (#107), Sasha's weight began to rise alarmingly fast in the last three months. Although he still carries his weight very well (see photo in #107, at his highest BMI since the publication of case report), I was worried about the trajectory and dismayed about OT's failure to help him maintain his weight during these last few months.
I was told about a PWS girl in Europe (who had been using OT for years) who benefited from taking drug holidays every 4-6 months to prevent down regulation of OT receptors. I was warned that she exhibited behaviors similar to her pre-OT treatment days (extreme hyperphagia) after the discontinuation phase at the time of restarting the OT. According to this anecdotal report, the child resumed moderate eating and weight loss after ten days of resuming the OT.
I decided that we needed to do something to interrupt the weight gain; we discontinued him for 10 days and restarted him (now on day 12) on OT. For Sasha, we didn't note any obvious changes in his eating habits during the week he had discontinued the OT- he appeared to eat moderately. However, we learned after the fact that he had been buying cookies from the cafeteria and eating them before school. I don't yet have corroboration from teachers about the timing of the cookie purchases but from what I can tell (per Sasha's report, for what that's worth), he started to buy and eat these cookies at about the time the OT was stopped. I believe he was still eating these cookies up until the 7th day after restarting OT. On the 9th day after restarting OT, he had a meltdown at school over some chocolate Easter egg candies in which he gathered the candies and fled with them (the eggs also vanished after he returned to class, surprise, surprise). The sign of food intensity in the form of a meltdown was totally reminiscent of how he used to be on a regular basis around food before we tried OT. Ugh. I'm glad I was warned about the possibility that his behavior could worsen after the 10-day discontinuation and that it wouldn't improve until he had been back on it for over a week.
He has been living with an unlocked kitchen and lax (if any) supervision in our home since May, 2017. Since his eating behaviors (calories ingested, food choices made, frequency and intensity of appetite) can only be observed episodically by us and by his (unreliable) self-reports, his eating behaviors cannot be accurately measured. Therefore, the only hard evidence I can glean is by his weight. On day 7 of his 10-day OT holiday, he weighed 83.4 kg. Two days ago (10 days after restarting OT), he weighed 82.4 kg and today, Sasha weighs 82.0 kg. In case anyone wonders if this is "water weight," we know for certain that it isn't because we calculate his weight always based on his weight when his sodium (as measured by a blood test) is at 140, right smack in the middle of the normal range. What makes his recent weight loss even more interesting to me is that he binged on the large quantity of chocolate egg candies just four days ago but he still lost weight! This is definitely the first time in months that he has not only NOT gained weight, but has even lost weight.
I know this is very early in our observations after his 10-day OT holiday and restart but something seems to have shifted. As a result, I am formulating some speculations about the necessity to manage his chronic dosing of oxytocin with drug holidays. I am also wondering about trying intermittent dosing once his weight plateaus. This very preliminary idea is based on Sasha's weight gain after chronic (one year +) OT administration, these early post-OT holiday observations of Sasha, and my reading of the scientific literature/correspondence with oxytocin researchers from which I have gleaned the following:
1. Anorexigenic effects of chronic oxytocin administration (done mostly on animal models) of OT can last up to 2-3 weeks after its cessation.
2. Oxytocin receptor binding may reduce as much as 50% after 10 days of administration.
3. Oxytocin is much more effective for weight loss on obese individuals than normal-weight individuals.
4. Anecdotal evidence has shown PWS kids in Europe who have benefited from long term, intermittent use of OT.
I believe the combination of the above findings theoretically suggest a good reason to try him on intermittent dosing when his weight stabilizes at a (hopefully) healthy BMI. I don't want to put the cart before the horse just yet since he still has some weight to lose but I am definitely intrigued by this idea. There is definitely a need to conduct more studies on dosing of OT, and especially on chronic dosing (if it is going to be used therapeutically in patients). In the meantime and since these studies are yet to exist, our experiment persists.
