I've had a kind of jittery teeth grinding effect ever since I started taking simvastatin a few months ago, and I noticed it was keeping me awake.
I started taking it mid day so I could get a nights sleep. I mentioned it to my endo and he said that sleep problems weren't a noted side effect of simvastatin and that it must be taken at night. Otherwise he seemed fairly disinterested.
If I take it right before bed as instructed, I'll drop off, but then be gradually awoken 1-2 hours into the night until I have to resign myself to the fact that I'm absolutely wide awake and I'll have to wait it out.
I googled it tonight, as it's 3am and I'm unable to sleep again and it turned up all manner of things regarding simvastatin and insomnia.
I took simvastatin for almost 4 years and never put my symptoms with that drug, including but not limited to insomnia, and a general achiness and crappy feeling similar to fibromyalgia. I was reading on here one day someone mentioned statins and the wave of negativity was palpable. I never had the problems with lipitor just with simvastatin. But the insurance company forced me to switch to simvastatin because at the time lipitor was not available generically. 2 months ago I switched back to Lipitor and the change has been dramatic. I haven't taken any type of pain medication for a month and a half. My sleep is fully resolved. I feel so good and while most doctors will shrug and say a statin is a statin for some people not all statins are the same. It's kind of like D your experience may vary.