Have been on Ambien for 4 nights. On the fifth night, I decided n...

I take Ambien CR as well, and it helps me get a good night's sleep on most nights. However, some nights I have severe sinus headaches that start while I am asleep. On these nights, I have horrible nightmares that seem to go on for long periods of time. I usually realize that I am having a nightmare at some point during it and force myself to wake up. Usually, my head aches so badly at that point and I am so freaked out by the nightmare, I can't get back to sleep for several hours. I figured out the connection between the headache, the weather (just before we have a rainy day), and the nightmares, but I didn't know that nightmares can also be a side effect of Ambien. Does anyone else tend to have nightmares on nights when they wake up with a sinus headache? Do you take Ambien CR as well? I'm just curious about which causes the nightmare--the Ambien or the sinus headache.