http://forums.psychcentral.com/bipol...-insomnia.html
Quetiapine(Seroquel) can certainly work, however if you don't need it for other reasons than using it solely for sleep should probably be a last resort. The possible side effects really outweight the gain since there are many other options.

I've tried a few different things.

Trazodone(Desyrel) has worked for me to some degree, but one of the more common side effects can be a pronounce "hangover" feeling or headaches the following morning. The headaches were particularly rough for me becuase they felt a lot like dehydration headaches and took a long time to go away.

Benzodiazepines [alprazolam(Xanax), clonazepam(Klonopin) and similar] tend to be habit-forming in the least and also it is easy to build a tolerance to them. They, too can sometimes create a hang-over type feeling.

I've tried eszopiclone(Lunesta) before- I found it really helped with staying asleep, but not as much getting to sleep. At one point I was taking a low dose benzodiazepine [I think it was alprazolam(Xanax)] with the eszopiclone(Lunesta) and it helped to get me to sleep and more often stay asleep with very little occurrence of hangover or fuzzy headedness in the morning. Eventually I just really realized I don't like the benzo class as a whole, and using just the eszopiclone(Lunesta) didn't help for ME to take care of everything all together. However, it is a helpful med for a lot of people. Overall I have the impression that there are fewer occurrences of strange sleep behaviors as can occur with zolpidem(ambien). One thing many people do notice with the eszopiclone(Lunesta) is a strange taste in the morning- it's kind of like a strange penny-type taste, but easily goes away.

I tried ramelteon(Rozerem) at one point, a melatonin-like medication that has little to no potential for abuse and can be very affective for people who have trouble getting to sleep initially. One of the other positive things is that there is also low report of withdrawal symptoms. I found it had a couple side effects-the most notable being that it made me extremely irritable [actually, it made me beyond irritable]. I have seen a few reports here and there of similar experiences but I have not found indicators of any factors which could consistantly predict who might also have that experience. The good thing was pretty much as soon as I stopped that went away. Ramelteon(Rozerem) has been helpful for a lot of people, just didn't work out for me.

What I most often use now is diphenhydramine- so Benadryl or ZzzQuil.
Please note that the ZzzQuil, while made by the same company, is NOT the same as any of the other actual Nyquil formulations.

I know one other poster mentioned taking triple dose of Nyquil- but this should be done with caution. Depending on which formulation, it approaches the recommended limit of acetominophen intake for an adult [4000mg/day]. It may seem like a lot, but one of the Nyquil's at triple the dosage already brings you to 3000mgs. If you take anything else with acetominophen in it, and if you do this regimen on a fairly regular basis you are giving your liver quite a work out. Depending on the frequency and amount of acetominophen you take, you could eventually start to damage your liver.

So it's important to realize what ELSE might be in cough and cold medications, not just the sedative.

What is sedating in the Nyquil formulations IS an antihistamine however, this is the same class of medications as diphenhydramine and they are the same generation. If the Nyquil is effective one could try diphenhydramine (Zzzquil or Benadryl) and it may work just as well- if you are taking the Benedryl for sleep, however, please ask your doctor or pharmacist for guidance on dosing.

I recieved the recommendation regarding dosage and frequency of Benedryl/diphenhydramine from two psychiatrists but that may not be appropriate for someone else's situation, and I also do not take it every night.

Another thing I will occasionally try is extremely strong-brewed chamomile tea. because I don't do it very frequently, sometimes this is in fact just enough to calm me and push me over the edge. There is significant evidence to support that chamomile has pharm anti-anxiety properties.
Valerian can also be helpful, but I've personally found chamomile to be more effective.

However, as with all altering substances, it is important to investigate any interactions with your usual medications- even if you are considering OTCs or herbs/supplements.

Both medscape.com and drugs.com have good drug interaction checkers and, of course, your pharmacist is always a good resource.