(Background: Parts 1, 2, 3, and 4)
Well, it has been not one but two weeks since I set up my Symlin experiment. Three vials, each with one part Symlin and ten parts Novolog insulin, set out on my desk, in the sun on the balcony, or carried with me in my purse. I was looking for precipitation, weird changes, anything that might indicate it’s not safe to mix the two substances.
And, two weeks later, there is no precipitate, no color change, no pH change, nothing. All three vials look exactly the same. I even set one up in an old pump, pumping into a Ziploc bag on a low basal rate with intermittent periods of suspension to see if I could cause an occlusion, or blockage, in the tubing.
Nothing. No observable changes whatsoever.
The first thing I realize is that “no observable changes” is a far cry from “no changes”– there could very well be serious changes in the pharmacokinetic properties of the insulin-plus-Symlin mixture that I could not see or perceive except by putting it in me and seeing unpredictable results.
The second thing I realize is that I’m a little disappointed. I was kind of hoping for something obvious– precipitate, powder blocking the tubing, a change in pH over time, a change in viscosity– anything to indicate, “Here is the problem with mixing the two solutions that I was warned about.” But all I have is the underwhelming conclusion that, well, mixing insulin and Symlin does not necessarily cause a problem. That doesn’t mean it doesn’t cause a problem; it just means I’m not certain whether it does cause a problem.
Sigh. An obvious problem, you see, would have been an easy answer: Okay, you can’t mix these two substances; stick with insulin treatment for now and wait until a better solution or dual chamber system is available for Symlin. No immediate change in habit and ritual necessary. Keep on keepin’ on.
But now I have a decision to make: do I start actually mixing Symlin and insulin in my pump cartridges? It’s easy to be gung-ho about the benefits of Symlin from afar, when taking it is still a distant possibility. But now that I actually have the option, I hesitate to make the decision. To be frank, I’m scared.
I’ve been using insulin for over 15 years now. Not once have I used Symlin. What if I start using Symlin and it’s like adjusting to first using insulin all over? How long will I have to play with amounts and basal rates and ratios before I reach at least the same level of knowledge and familiarity and habit that I have now with insulin? And insulin is hard enough to manage on its own– there are so many variables at play that it’s hard to predict how much is the right amount for a given scenario. Why complicate that by adding Symlin in to the mix? And that’s all without even taking into account the possibility that mixing Symlin and insulin will actually have additional complications, above and beyond taking the two separately– like changing the pharmacokinetic profile of each substance, or causing occlusions in the pump.
In other words, to echo the cry that I ascribed to conservative endocrinologists– if it ain’t broken, why should I go about fixing it?
But, I guess, to return to my original complaint, it is broken. The non-diabetic makes the hormone amylin, and amylin activates all sorts of pathways in the body, including those that control gastric emptying and those that indicate a sense of satiety to the brain. Those specific benefits are desirable to me, but even more so I want to know that I am doing everything possible to maintain the delicate hormonal balance that evolution has defined within the human body. I want to minimize the damage done over time to unknown parts of my body because my immune system attacked my beta cells. I want to, as much as possible, keep everything that is broken about me in working order so that I can live a long, healthy, happy life. With my eyes and nerves and kidneys intact, thankyouverymuch.
But, all that said, I also don’t want to have to face months of unpredictable blood sugar levels as I try to introduce a new hormone into the equation. I don’t want to deal with the crappiness of being low and high unexpectedly. I don’t want to mess with my routine.
In other words, yes, I fear change. To those of you who are not diabetics, this may not seem too big a change. But part if me is fighting back tears right now. Fifteen years! No amylin in me. Only insulin coming in, delivered subcutaneously. Not perfect by any means, but at least its evil is a known evil. And now you’re (I’m, I guess) asking me to go and do something different? Something unknown? Something untried?
“And the people spoke against God and against Moses: ‘Why have you brought us up out of Egypt to die in the wilderness? For there is no food and no water, and our soul loathes this worthless bread.'” Num 21:5
But I can’t stay in Egypt forever, can I? So, will I start using Symlin? Will I start mixing the two hormones?
I don’t know yet. Ask me again in a week. I can’t promise I’ll know then either. It’s a decision I have to make, but for a little bit longer, I’ll just shut my eyes very tightly and pretend the world is perfectly stable and unchanging.
Please note: I am not a doctor, or a medical professional, or even a chemist. The above is intended to be purely informational, and is based on my own research; it has not been independently verified, and is not medical advice.
OK, I’m just so curious about this whole topic, I’m dying to try it myself, and I’m so impressed that you’ve become a one-woman research team, even (maybe) playing the part of the rat! Along with reaching out to the researcher Scott listed, is there a way to make contact with the few other humans who have gone on record as having mixed Symlin and insulin in their pump? This mom: http://www.lisashouse.typepad.com/ commented on Kerri’s Six Until Me Symlin post: http://sixuntilme.com/blog2/2010/08/debating_symlin.html and mentioned that she mixes Symlin in her daughter’s pump. Possibly her endo helped her out with this, as… Read more »
@Scott– funny enough, I did back when I read that paper, with no response. I did, though, after posting, get an email from an Amylin medical research director, warning me to only use Symlin as directed. A former Amylinite I spoke to, who could speak more freely, did not recall anyone having found anything horrid that comes from mixing the two, but said that research in that domain had been lacking. And all that sums to: I haven’t done it yet ;) As Stella suggested above, I suppose this is why the FDA usually requires extensive testing of drugs and… Read more »
True but you could always reach out to the study’s principle author, Dr. Mario Sylvestri about any insights they may have on mixing in advance. One thing to be concerned about is whether amyloid proteins might form; most recently, this was reported in MannKind’s Afrezza leaving amyloid proteins in the lungs, which can be cancerous (all that to avoid a needle?). Nevertheless, you might try reaching out to Dr. Sylvestri. His correspondence address is at Amylin Pharmaceuticals Inc., 9360 Towne Centre Drive, San Diego, CA 92121, e-mail: email@example.com, although I believe he is based outside Amylin’s San Diego HQ in the… Read more »
@Scott– Yes, I read that study back when reviewing the literature (see Part 1), but, unfortunately, they were only looking at mixing the two in syringes immediately prior to injection. Having a sitting mixture in a pump introduces a new set of complexities for which I have yet to see any published data. It seems that the general push is for dual-chambered pumps, so there’s little reason from a marketing/big-pharma perspective to pursue the mixing direction too far.
According to a 2005 study published in the American Journal of Health-System Pharmacy found that mixing Symlin (pramlintide acetate) with insulin (both rapid-acting and long-acting analogues) was entirely feasible and did not affect the pharmacodynamics of glucose, the pharmacokinetics of insulin or of pramlintide in a clinically significant manner. Be advised that this was a very small study (51 individuals), but still validates your thinking on this. For reference to that journal submission, please see: http://www.ajhp.org/cgi/content/abstract/62/8/816.
I think your hesitation is why they experiment on rats first, before humans.