I'd say the best drugs to take alongside an opiate for
A. The itch, B. Any nausea you might have and C. Potentiation of the opi's sedative effects are 1st generation antihistamines like the (usually, in most places) OTC promethazine and/or diphenhydramine. My personal favorite (and from what I've read and heard, most folks prefer this one when given the choice) antihistamine for opiate potentiation is hydroxyzine (I strictly use it for potentiation because I'm not troubled by the side-effects really. Each one of these 3 is very effective against side-effects from opioid use though. Hydroxyzine is just my preferred potentiator, but for other purposes they all work fine. They all have sedative effects that boost the opiate sedation (hydroxyzine the most IME), but are also good antiemetics (counters nausea) and of course antihistamines (counters the itch) drugs.
I would never in a million years take seroquel for the itch. It has horrible side effects.
Also, @4-ho-keith; when you say getting no sleep. Because of the itch you mean right? Because the first generation anti histamines I mentioned are often prescribed off-label as sleep aides. And IMO/E not enough doctors do this, and go for the addictive solutions way too quickly. This is a great first-line treatment IMO. Because they're quite effective as a sleep aide (for me anyway), and even if they aren't for you (@4-ho-keith), I very much doubt they would ever keep you up. So I'll assume you mean that the itches sometimes do, which I can imagine would suck.
@op; I'd definitely try one of these. I think one of the 2 OTC ones I mentioned should work just fine. Hydroxyzine isn't necessary imo unless you can get it really easily, IME diphenhydramine or promethazine are almost as good as potentiators and work just as well if you're bothered by itching and/or nausea.
I hope this helps.
