Action of naltrexone at normal<unk>  Naltrexone and its active metabolite 6-β-naltrexol are competitive antagonists at μ-opioid and κ-opioid receptors, and to a lesser extent at δ-opioid receptors. Standard therapeutic<unk> s of naltrexone blocks these receptors, which does two things; it prevents inhibition of GABA receptors (normally, signalling through the GABA receptors inhibits the activity of neurons; many recreational drugs inhibit GABA and thus "free up" neuronal activation; preventing inhibition of GABA allows GABA's normal inhibition activity to take place) and it blocks dopamine release (many recreational drugs stimulate dopamine release, which is part of the brain's reward system that creates pleasure). Hypothesised action of<unk> <unk>  refers to<unk> s about 1/10th the size of the<unk>  used normally, typically 4.5 mg or within a couple of milligrams of that value. It is hypothesised that<unk>  may inhibit opioid receptors and therefore cause the body to increase production of endorphins and upregulate the immune system; it may also antagonize Toll-like receptor 4 that are found on macrophages, including microglia, possibly resulting in the reported anti-inflammatory effects. These apparent effects have not been seen at standard<unk> s or in major trials. Researchers have also examined "ultra-low-doses" of naltrexone at microgram, nanogram, and picogram<unk> s, that are co-administered with opioid analgesics with the goal of increasing pain relief and reducing side effects.
Low-dose naltrexone
Methadone maintenance
Extended-release morphine
Nicotine patch
Nicotine gum
MDMA-assisted psychotherapy
Naltrexone
Atomoxetine