Ironically, buprenorphine and methadone are used both to control pain and to control addiction to pain-controlling drugs. This is due to their complicated interactions with our endogenous opiate system.
Buprenorphine (Subutex) itself binds more strongly to receptors in the brain than do other opioids, making it more difficult for opioids (or opiates) to react when buprenorphine is in the system. The blockade effect also has the result of blocking endogenous endorphins from binding to receptors, which can lead to psychological alterations in mood and mental capacity. This can cause cognitive and memory deficiencies via blockade of the reward system, which is pertinent to memory formation and normal mental function.
Switching from buprenorphine to other opioids is generally safe but requires careful dosing in the first few days. Initially, high doses of the alternate opioid are required to overcome buprenorphine’s high receptor affinity. Over the next few days, these doses are reduced as buprenorphine’s receptor blockade wears off. This issue is of particular relevance when the drug is used for analgesia: adequate levels of analgesia may be difficult or impossible to obtain without high (and potentially dangerous) levels of the alternate opioid.
This is the greatest fear: what happens if you are injured and experience a dramatic increase in pain? The buprenorphine will keep other opiates from having an effect, except in massive doses, which these days may be impossible to get from doctors.
Methadone also blocks the effects of other opioids at higher doses; however, under ~40 mg, the blocking effect is less pronounced. At commonly used methadone maintenance doses, the degree of blockade is similar to that produced by equivalent buprenorphine doses.
Methadone, similar to buprenorphine, is another opiate that has subtle effects on the psyche. This troubling aspect has never been researched, but surfaces in patient stories. In addition, there is agreement in drug forums that “methadone has the WORST withdrawal of any drug ever put on the market, even heroin.”
So it’s ironic that methadone is the drug used for opiate abstinence maintenance – it is definitely more addictive and there is more danger of overdose (due to potency), but it has the advantage of being a controlled dosage, unlike street drugs. While supposedly beneficial, this moves addicts from less potent and less addictive opiates to a stronger, more addictive drug under the government’s control.
There are a number of broad classes of opioids:
Natural opiates: alkaloids contained in the resin of the opium poppy, primarily morphine, codeine, and thebaine, but not papaverine and noscapine which have a different mechanism of action; The following could be considered natural opiates: The leaves from Mitragyna speciosa (also known as kratom) contain a few naturally-occurring opioids, active via Mu- and Delta receptors. Salvinorin A, found naturally in the Salvia divinorum plant, is a kappa-opioid receptor agonist.
Esters of morphine opiates: slightly chemically altered but more natural than the semi-synthetics, as most are morphine prodrugs, diacetylmorphine (morphine diacetate; heroin), nicomorphine (morphine dinicotinate), dipropanoylmorphine (morphine dipropionate), desomorphine, acetylpropionylmorphine, dibenzoylmorphine, diacetyldihydromorphine;
Endogenous opioid peptides, produced naturally in the body, such as endorphins, enkephalins, dynorphins, and endomorphins. Morphine, and some other opioids, which are produced in small amounts in the body, are included in this category.
It seems the fully synthetic opiates are more potent and dangerous than the semi-synthetic ones usually used for pain control. This is progress?