Muscle craps. My specialty. I have been getting them since I was a kid who used to jump up out of bed screaming in pain as my a of my legs was bent over on other leg. Craps that would tear muscles that would leave me limping for days sometimes even longer.
During 1996 as my hydrocephalus started to cause major problems for me I was at my worst. I looked like a Hollywood special effect.
Watch the movie American Werewolf in London. When the lead character changes from a human to the Werewolf you could see the muscles twitch and run up & down under the skin of this arms. I looked just like that.
The pain was awful. My toes would cramp up like they were being pulled into my foot. Cramps in my calf's, thigh's, abdomen, chest, my finger's.
I have pictures of my toes cramped up to show the doctors.
I used Quinine which helped but not without bad side effects. Then I talked to my neurologist in Maitland Florida and we tried numerous drugs until we found what worked. Clonazapam and Cyclobenzaprine.
The only problem with Clonazapam is it's a controlled substance and I need a new hand written prescription every month. I don't know why. I get no rush or have anything happen while taking it.
I still get some muscle craps but they are minor and are easy enough to live with by taking these two drugs.
As for possible long term side effects? I've been taking them for years with no problems.
Both my daughter and my sister have the same problem as myself just nowhere near as badly as myself. Lucky for them.