For God-sake's
DO NOT, I repeat DO NOT EVER IV codeine, DHC or hydrocodone. Doing so can cause potentially fatal pulmonary edemas. The injectable version of codeine that 80mg was talking about is for IM (intra-muscular) and SC (subcutaneous) use only, and even then is rarely used as there are far better parenteral (injected) narcotic pain medications. DHC follows the exact same principle, any injectable forms of it are for IM or SC use ONLY.
Anyways, to answer your question

:
Having taken DHC a few times, it actually is one of the more speedy opioids, IMHO and I also found that it gave me insomnia. It definitely will make you more talkative and a more energetic at the doses that you prescribed. In addition, they were the Contin version, meaning that they're continuous release as opposed to immediate release, the difference in the two in terms of the effects that you get can oftentimes be like night and day. The bromazepam would definitely help, but don't exceed a 3 mg dose the first time around. The combination of opioids such as DHC and benzos such as bromazepam can be lethal, so when combining the two, especially without a tolerance, you want to keep doses low. 3 mg of bromazepam would definitely help you sleep. Bromazepam is a very good benzo, IMHO, and can be quite enjoyable. Again, I want to strongly urge you to not exceed 3 mg of bromazepam when taking the DHC your first time around. You didn't indicate what your tolerance is, so in this case, ALWAYS start low. Once you get a good idea of how a dose will affect you, then you can raise/lower doses as needed.