SUBOXONE, COCAINE, AND OPIOID ADDICTION

In my practice, I have observed that it is fairly common for people on suboxone to use cocaine.  One might ask whether using cocaine has an effect on recovery from opioid addiction.

Here I am not referring to the obvious risks of using any street drugs, rather, I am asking whether using cocaine makes recovery from opioid addiction more difficult.  After all, cocaine isn't oxycodone or heroin, the overdose risks is relatively low, and it won't lead to opioid type withdrawal, so why not?

There is a problem with the logic that comes from the mechanism of addiction and the changes in your brain that result from long term opioid use.  It is related to how the reward system of your brain is affected by either opioids or cocaine, separately or together.

Both drugs (meth too, but that's another horror story) cause the release of large amounts of the neurotransmitter dopamine, (DA), in parts of your brain (specifically, the nucleus accumbes (NA) which project to the higher consciousness centers (front cortex, and other areas).  Dopamine makes its target cells fire electrical signals and the more dopamine stimulus there is, the more reward response is triggered.

The release of DA in excess of normal amounts leads to a compensatory response from the cellular targets:  they adapt to reduce their sensitivity to DA.  This kind of accommodation is characteristic of all living things, and is normal:  if it gets hot, you sweat to cool off, if you get hungry, you eat, if you drink too much water, you pee.

In addiction, this compensatory decrease in sensitivity to DA leads to a positive feedback loop.  When the drug is absent, and the DA levels drop to normal, there isn't enough present to stimulate the reward centers, and craving for something to increase the DA sets in.  When this happens, the learned behavior is to get something that will release lots of DA, that is, drugs.  Then the cycle goes around again, and over time the sensitivity to DA decreases a little more.

As this progresses, craving morphs into withdrawal, which is the result of more generalized changes in the responses to DA and other neurotransmitters affected by the drug.  Here is where cocaine and heroin, for example, differ.  They overall effects of cocaine are less direct than heroin.  Heroin causes increases in the production of DA by stimulating opioid receptors, especially the mu receptors. These receptors have effects throughout the body, on gut motility, breathing, and the sympathetic system, in addition to the DA producing neurons in the reward system.  When the heroin stimulus to mu receptors is withdrawn, the effects are diarrhea, sweating, agitation, and the other aspects of heroin withdrawal.

This is in contrast to cocaine, which is more focused in its effects.  Rather than directly stimulating DA production and release, it inhibits the enzymes which take up DA out of the synaptic cleft between NA neurons and the target neurons, increasing its effects.  It is little like the effects of antidepressants, like prozac, which have similiar effects on serotonin re-uptake.  When withdrawn, the effects are much less intense.

But both heroin and cocaine withdrawal have craving and depressed mood as long term effects, because these are directly related to the loss of DA excess to which the person who uses either of these drugs is accommodated.

The process of recovery from chronic use of these drugs depends on resetting the DA sensitivity, so that normal non-drug induced levels of DA are adequate.  What this means is that excessive dopamine stimulus from cocaine, like any excessive DA stimulus, prevents the reset required to fully recover from opioid habituation.  So using cocaine perpetuates the response to excessive DA, making relapse to opioid use more likely.

So, I wish I could say "Oh, go ahead, party on with all the blow you can afford", but I can't, sorry!  Stay away from cocaine too, and even more so methamphetamine, the effects of which on dopamine are about a thousand times that of heroin; your future depends on it.