They would potentiate each other, it would be like if you are used to taking a shot of vodka and then you also start taking a shot of whiskey with it, you would be feeling more potent effects from both. They are both sedatives.
There was a time when that idea wasn’t as horrible…
I can get twice the hit? Tell me more…
Aging sucks…
Well, the zolpidem did give you hallucinations, so putting it together with a benzo could result in more intense hallucinations, such that you might think the time-space continuum had inverted while under the influence. 
Seriously though, we counsel not to mix the two because they have duplicative mechanisms of action. They both hit the same binding pocket on the GABA-A receptor complex (somewhere in between one of the alpha subunits and the gamma-2 subunit), positively modulating (making it work better) the effects of endogenously released GABA. Generally speaking, our training tells us that combining two agents which work by the same mechanism of action is a poor choice–we’d call it an example of irrational polypharmacy. In this specific instance, it provides, as grude states, a greater intensity effect. While you might think this is a good thing for sleep, you have to remember it’s also intensifying effects on cognitive function, memory, and risk of addiction, for what are argued to be minimal benefits.
Beyond that, however, we attempt to ask the question of what’s causing the insomnia. In someone with chronified pain and/or an anxiety disorder, the odds are weighted towards either the pain, the pain treatment, or the anxiety causing/worsening the insomnia, and zolpidem in particular, but also the other z-drugs, are unlikely to treat the underlying pathophysiology if the pain or anxiety states are the cause. At best, the z-drugs are masking the underlying cause. We’d rather the patient and physician work together to figure out what the cause is and treat that, instead of just masking the symptom of insomnia.
Should you live in fear of falls or fractures or accidents? No, that’s probably not going to help you (and might actually encourage behavior capable of promoting pain, anxiety, or sleeplessness). Informed consent does require that you are at least made aware of the increase in risk with the therapy compared to it’s expected efficacy so that ultimately you can make the decision if the benefit outweighs the risk.
Another possible downside to the use in combination beyond those already mentioned is that the combination likely increases the rate at which tolerance to one or more beneficial treatment effects occurs. It’s hard to say by how much, since the combination of a z-drug and a benzodiazepine together hasn’t been studied (so far as I can find).
It’s unlikely you’d get twice the hit with the combination. At least some of each of the two drugs are going to be competing with each other for the shared binding pocket, after all. At low doses of both agents, you’d have to worry less about this due to more open receptor site availability versus higher doses of one or both drugs. Nor would the combination necessarily increase the overall amount of time of positive effect you get from the drug(s) as free drug is more easily cleared from the site of effect than bound drug is, so you might end up with one or both drugs increasing in concentration in fat tissue (where release back into the bloodstream is probably lower than a rate necessary to increase CNS levels by all that much on it’s own), not staying put in the CNS where you’d want it for sleep-promoting or anxiety-relieving effects.
Thanks again for your time and thought - I am a good boy now (although I do sorta wish for just one more little trip, for old time’s sake.
Know any conditions the treatment for which is lysergic acid diethylamide?
The insomnia is puberty-onset - in Medium School, I remember being awake at 02:00. It’s been a bitch my entire life, fanally ending with 2 diphenhydramine gel caps (I’d burn off the tabs as they hit) and about 1/4 - 1/3 l of 100 proof vodka.
That’s when I let the doc start playing with the benzos.
Now the old chemistry doesn’t work, and I either find a good pill or don’t sleep (record: 4 days waiting for “natural” sleep before resorting to pills).
Last night the pills failed again - meaning double dose tonight of a benzo.
Since this has become more about medical advice than the legality of Canadian pharmacies, let’s move it to IMHO.
Colibri
General Questions Moderator