Xorkoth
Bluelight Crew
My experiences with this are as follows. All drugs cause tolerance to themselves (obviously). Different drugs within the same families, that hit the same receptors, cause cross-tolerance and cross-dependence, but to a lesser degree than using the same drug over and over. However, rotating opiates is going to lead to opiate dependency. Likewise, using another opiate to get off of an opiate doesn't work, for the most part, you just prolong the addiction, and switch dependencies to the new one if you dose it more than a few times.
As for different classes of drugs that affect the same systems, rotating them helps a lot to reduce tolerance buildup and dependence, but it is my experience that over time, even if you escape acute withdrawal (say, by rotating benzos and alcohol), you will still cause downregulation of GABA receptors, and you will experience rebound and light dependence, which is less severe than if you dose one or the other every day, but which nevertheless is dangerous and will lead to suffering.
The most sustainable way to get high every day on addictive drugs is to rotate drugs which have totally different mechanisms of action, and use as many classes as you can, to put more time between each type of drug. For example, benzos one day, opiates the next, stimulants the next, alcohol the next, gabapentin the next, dissociatives the next... if you can throw something not physically addictive, like weed (or stims, or dissos) or skip some days altogether, that is going to help make it more sustainable. But this is a very slippery slope and it takes herculean effort to avoid slipping into a serious problem, and this sort of thing often leads people into being physically dependent on multiple drug classes at once, which is a trap you really do not want to fall into. Also over time this will lead to greater and greater difficulty just not taking anything, and will long-term downregulate your receptors in various systems so that if you try to stop, you will be feeling all sorts of off, even if you escape acute withdrawals.
It's playing with fire, and the more you do drugs, the more you want to do drugs. It's best to try to work on spending more time sober, as really, the only long-term sustainable way to use drugs is to use them occasionally, rather than all the time. But, as they say, do what I say, not as I do...
Gabapentin doesn't have any effect on GABA or NMDA receptors, it is purely an antagonist of voltage-gated calcium ion channels (that is the definition of a gabapentinoid, something that does that). The mechanism for why it gets you high isn't fully understood, but it probably leads to an increase in various neurotransmitters downstream. It may indirectly lead to an increase in GABA (I have read conflicting information about this), but it's not at all the same as a benzo or alcohol. Although actually alcohol does have some ion channel blocking properties (alcohol hits a wide array of receptor sites, it is a slutty chemical), but I'm not sure if it's voltage gated calcium ones.
