Opioids are a class of drugs that derive from, or mimic, natural substances found in the opium poppy plant. Opioids work in the brain to produce a variety...

The opioid epidemic, also referred to as the opioid crisis, is the rapid increase in the overuse, misuse/abuse, and overdose deaths attributed either...

Opioid receptors are a group of inhibitory G protein-coupled receptors with opioids as ligands. The endogenous opioids are dynorphins, enkephalins, endorphins...

Opioid use disorder (OUD) is a substance use disorder characterized by cravings for opioids, continued use despite physical and/or psychological deterioration...

An opioid antagonist, or opioid receptor antagonist, is a receptor antagonist that acts on one or more of the opioid receptors. Naloxone and naltrexone...

The μ-opioid receptors (MOR) are a class of opioid receptors with a high affinity for enkephalins and beta-endorphin, but a low affinity for dynorphins...

Opioid withdrawal is a set of symptoms (a syndrome) arising from the sudden withdrawal or reduction of opioids where previous usage has been heavy and...

There is an ongoing opioid epidemic (also known as the opioid crisis) in the United States, originating out of both medical prescriptions and illegal...

An opioid overdose is toxicity due to excessive consumption of opioids, such as morphine, codeine, heroin, fentanyl, tramadol, and methadone. This preventable...

The κ-opioid receptor or kappa opioid receptor, abbreviated KOR or KOP for its ligand ketazocine, is a G protein-coupled receptor that in humans is encoded...

an opioid antagonist: a medication used to reverse or reduce the effects of opioids. For example, it is used to restore breathing after an opioid overdose...

Buprenorphine, sold under the brand name Subutex among others, is an opioid used to treat opioid use disorder, acute pain, and chronic pain. It can be used under...

Benzimidazole opioids, also known as nitazenes, are a class of synthetic opioids with an unusual benzimidazole structure often referred to as "opioid New Psychoactive...

Revia among others, is a medication primarily used to manage alcohol use or opioid use disorder by reducing cravings and feelings of euphoria associated with...

be more pronounced in opioid-naive subjects than chronic opioid users. In chronic opioid users, such as those on Chronic Opioid Analgesic Therapy (COAT)...

The δ-opioid receptor, also known as delta opioid receptor or simply delta receptor, abbreviated DOR or DOP, is an inhibitory 7-transmembrane G-protein...

historically been consumed via chewing, smoking, and as a tea. Kratom has opioid-like properties and some stimulant-like effects. As of 2018[update], the...

Opioid use during pregnancy can have significant implications for both the mother and the developing fetus. Opioids are a class of drugs that include...

Dolophine and Methadose among others, is a synthetic opioid agonist used for chronic pain and also for opioid use disorder. It is used to treat chronic pain...

are opioids. Examples of such opioids are: pentazocine, agonist at the kappa (κ) and sigma (σ) and has a weak antagonist action at the mu opioid receptor...

and OxyContin (which is the extended release form), is a semi-synthetic opioid used medically for treatment of moderate to severe pain. It is highly addictive...

Opioid-induced hyperalgesia (OIH) or opioid-induced abnormal pain sensitivity, also called paradoxical hyperalgesia, is an uncommon condition of generalized...

Opioid peptides or opiate peptides are peptides that bind to opioid receptors in the brain; opiates and opioids mimic the effect of these peptides. Such...

including OxyContin. Purdue Pharma has been criticized for its role in the opioid epidemic in the United States. They have been described as the "most evil...

archetypal opioid, and other opioids (e.g., codeine, oxycodone, hydrocodone, dihydromorphine, pethidine) all exert a similar influence on the cerebral opioid receptor...

Tramadol, sold under the brand name Ultram among others, is an opioid pain medication and a serotonin–norepinephrine reuptake inhibitor (SNRI) used to...

after a period of drug abstinence can also induce overdose. Cocaine and opioid users who inject intravenously can easily overdose accidentally, as the...

Opioid agonist therapy (OAT) is a treatment in which prescribed opioid agonists are given to patients who live with Opioid use disorder (OUD). In the case...

carfentanyl, sold under the brand name Wildnil, is an extremely potent opioid analgesic used in veterinary medicine to anesthetize large animals such...

Hydrocodone, also known as dihydrocodeinone, is a semisynthetic opioid used to treat pain and as a cough suppressant. It is taken by mouth. Typically it...