Is it OK to take night-time cold medicine to fall asleep?

[devhead]

I have difficulties falling and staying asleep. I had a cough recently, and took a night-time cough syrup (similar to Nyquil cold and cough), and it helped me sleep all night long. I kept taking it after the cough was gone. Does anybody know if this is bad for me?

I'm in my 30's, I eat right, stay to a regular bedtime schedule. I've taken sleeping pills off and on for years (mostly on). I've tried Melatonin. Still, nothing works that great. I can't imagine that the cough syrup is worse than the sleeping pills.

Any thoughts would be appreciated!