Personally, I wouldn't recommend using prescription or over-the-counter sleeping pills to ward off insomnia. I've struggled with insomnia for years, and none of those drugs helped me one bit. In fact, the after effects were more painful than insomnia itself. The best method that worked for me was to simply change my lifestyle and make full use of natural sleep products. Here's a list of things that worked the best for me:

1)Get plenty of sunlight and exercise
2)Melatonin supplements (melatonin is a hormone produced by the brain that indicates to the body when it's time to sleep)
3)Good quality eye mask
4)Sleep optimization programs
5)Avoiding caffeine
6)Brainwave entertainment
7)Consuming sleep-inducing foods (e.g. cherries, grapes)

I would only look to prescription pills as a last resort, because these medications only succeed as a temporal fix. It doesn't cure your insomnia, and you'll forever be dependent on them. I hope this helps and I wish you the best of luck!

Source: http://www.insomnian.com