Are depressants additive or exponential when combined?

[frontbluntt]

What I mean is, say you combined, for example, GHB and an opiate, or benzos and alcohol, and so on.

Does your breathing slow the combined amount of what it would have slowed were the two drugs on their own (say one drug decreased your breathing by 10bpm and the other by 15bpm, thus your breathing slows 25bpm), or is it exponential when combined (the two aforementioned nameless drugs would combine to produce a difference greater than 25bpm)?

Or does it depend on the drugs? For example I am under the impression that mixing benzos and alcohol is relatively safe (physiologically) compared to benzos and opiates, for example.

 

[Alex000]

When mixing CNS depressants, it is NOT 1 + 1 = 2, unless you are adding one benzo to another benzo, for example, and there you just have more benzo effect. CNS depressant combo's are potentially very dangerous; some may be less dangerous, but they are all quite risky. Now, if the average individual takes 0.25 mg Xanax and sips on a glass of wine, he or she is probably not in grave danger, but I'd bet with no tolerance he or she would be feeling it and have their inhibitions quite relaxed, perhaps as if they'd had three or four drinks in them. With smaller dose combinations, often the danger comes in more with the error in judgment that it will be okay to take more, however even the wrong 'small dose combinations' can be very dangerous. To answer your question with simplicity, exponentially synergistic in physiological and psychological effects; NOT additive. Always, know your personal limits, set those limits, be careful and knowledgeable, and as prudent as you can be, when mixing CNS depressants.

 

[frontbluntt]

Thank you, you effectively answered all my questions in one post!
Very much appreciated!