Minh,

The insomnia is caused by the opiate pain medication (fentanyl, oxy etc...) due to how those drugs work on the brain. So that's a likely cause of the insomnia...that and stress probably.

The sweats etc are more then likely withdrawel symptoms, from the reduction in dosage from the fentanyl (due to the danger of coming off fentanyl please work with you medical professionals to taper down!!) and maybe the lorazepam. Due to the fact you are on another benzo (benzodiazepine, the temazapam) it's unlikely that it's withdrawel from the lorazepam though..but stranger things have happened for sure.

The benzo's did little for me in the way of sleep. They are for "short term" insomnia only and I really don't think they are effective when used to treat insomnia brought on by the opiates. I was put on Ambien first, then Lunesta in conjuction with a benzo...even that was ineffective and cause episodes like sleep walking etc. I'd never take them again to be sure.

I'm not sure what the medical marijuana laws are like in Australia...but that's what I'd use for help sleeping. As long as you are on the pain meds, insomnia will likely be an issue..even for a while after you've stopped taking them. An FYI, both fentanyl and benzo's will cause fatigue/exhaustion.

keep your chin up, hope it helps

Eric