You can, but alot of people would advise against it. Most of the deaths from benzodiazepines(xanax, valium, ativan, etc) come from mixing them with opiates and/or alcohol. They are all CNS depressants and opiates/alcohol suppress your breathing, which is even more pronounced when mixing with benzos and can be dangerous. All that shit out of the way......I have mixed opiates with benzos numerous times. It depends on the dosage, really. If it's a pretty low dose of each, then I don't see why you couldn't mix them. Just be careful.
Yes, in higher doses that is a dangerous combination. And NEVER combine methadone with benzo's. (you didn't mention what kind of opiate so...). Even in low doses you could die.
wrong forum. but... yes, valium is known to increase opiation. but in larger amounts opiates and benzos are a dangerous combo.