I've not heard of this one before but I do know that the majority of the population has a magnesium deficiency. Mark Hyman, MD has mentioned that the medical community used to use this natural treatment in emergency rooms. https://www.youtube.com/watch?v=GUWL1o2hSrs
Carolyn Dean, MD has published a book on the benefits. https://www.youtube.com/watch?v=d55y4yOnn3c
Also, I've been taking it for years and no longer have those leg tremors from which so many of us suffer. No longer do I wake up in the middle of the night with a charley horse. I did find that a lot of doctors are quick to prescribe these meds that have side effects. Trying natural things would be my first choice. I was able to discard a prescription when I began the magnesium.

I take Primadone as well as Inderal 40 mg TID. I prefer Nadolol but it is real expensive (the co-pay), even on Medicare. Just any old Beta-blocker won't work. It has to be one that crosses the blood/brain barrier. Many Beta-blockers are geared more toward heart or blood pressure problems and do not cross the BB barrier.

I was taking a Beta blocker first, then Primadone was added.

As it seems with most meds now-a-day, there as a period where you have to adjust to the med.

I find BOOST 95% oxygen helpful to get thru my exercise session. You can buy this without a prescription, and it also helps when you have excessive spams, and tremors. It stops the tremors, spasms and pain in 10-20 min. You can buy online at Walmart for $10 per can for 150 inhalations. I buy it from Medical suppliers on ebay for $7 a can. Also available at Amazon. I was diagnosed with MS in 1988, and have had great relief with oxygen. Hope this helps all like it has helped me.