Thanks for your long and thoughtful reply. I just think there are other factors to consider that make Iron Dextran a viable option- YMMV.
Reading further in the science direct article
https://www.sciencedirect.com/science/a ... ia%3Dihub "Evidence-based and consensus clinical practice guidelines for the iron treatment of restless legs syndrome/Willis-Ekbom disease in adults and children: an IRLSSG task force report" you quote:
"5.5.4. Expert-consensus clinical recommendations
There is a lack of data on LMW iron dextran for the treatment of RLS,
but there is substantial clinical experience that shows it to be clinically effective in both anemic and non-anemic RLS patients. "
People have different criteria for deciding which treatments they will take and under what conditions. One reasonable criteria is the one you give, which is requiring Level A evidence. I love clinical trials and objective evidence (just ask the people around me), and I prefer to have Level A evidence. It drives me nuts when treatments go against objective evidence, e.g., take a treatment when there's evidence it doesn't work. But I'm willing to take other evidence if it meets my personal test of objectivity. We need to remember that 40-60% of the drugs prescribed are for off-label purposes, i.e., there's never been FDA approval. Doctors don't just do this willy-nilly- they have evidence convincing them to do it.
For me, the following meets that test: if you watch the rls.org webinar on Iron and RLS, Christopher Earley, no mean expert:-) says at approximately 43:45 that he uses iron Dextran. Now prior to this point, all of the numbers he uses in explaining iron injections are from the Injectafer studies- these studies are the gold standard . So those are the numbers he uses in his presentation. And then he adds this one sentence statement immediately, saying what he does- give iron dextran. This clinical practice is obviously the sort of thing that precipitated 5.5.4 above.
In short, he prescribes it and it works. BTW, he is one of the authors of two of the level A studies, so he knows Injectafer and dextran both really well. One can speculate as to why one vs the other, but an obvious candidate is cost. I google dextran and got $300-600 a treatment. For Injectafer, at drugs.com it appears to be about $1700 for 1000 ml JUST for the drug; costs at other places may vary, and the description is typically "expensive."
Sidebar: One conclusion that can't be made from the above article is that Injectafer is better than dextran. That's not what the article says. The studies on dextran don't miss out on level A evidence because of lower efficacy. The problem is that the data from the dextran studies isn't good enough, i.e., the studies weren't well enough done. So I wholly agree with the statement that Injectafer has "the best evidence of efficacy" due to the fact that they have high quality studies that prove efficacy. Dextran does not. But it has not been proved that Injectafer is a better formulation than dextran for rls. THis is a subtle point, but an important one. Someday, hopefully soon, someone will do some high enough quality studies on dextran so we'll know if there's a difference in efficacy.
Going back to Dr. Earley- if he thought there was significant issues with efficacy, he wouldn't be prescribing dextran. And if the authors of the above article thought there was a problem with people prescribing dextran, 5.5.4 wouldn't be there.
This is more than an academic question for me, as I'm hoping to be able to get an iron injection. I'm not sure that I fit the guidelines as I've been in treatment for some time, but I'm still not symptom free and dealing with side effects of medications.
So if I can get physician approval, my preference is Injectafer. But if I can't get injectafer due to cost and insurance not paying it- I'm comfortable with the evidence for iron dextran. It's still not cheap- but one of my meds, Horizant, is running from $45-$200/month after insurance already. If the iron works, it could actually save me money. No guarantees. But it looks like a reasonable "risk".
Back to the original question in the thread: if you can't get an insurance company to pay for Injectafer, and you really want iron, especially if you're hurting, one option might be to pursue the Dextran route.
As always, there are differing opinions.
![Smile :-)](./images/smilies/icon_smile.gif)