Trazodone
"I could always fall asleep, but could not stay asleep.  Three hours a night was normal.  I needed help and Ambien, etc. were harsh.  The doctor suggested trazodone and I tried it.  She said it might take time to work- but that first night I slept 9 hours.  I've been taking it for four years and it changed my life.  No side effects except for drowsiness on days 1-2 and if I'm off of it for any time.  I take 50 mg and am a 200lb healthy male.  This medicine is under-prescribed for this indication."