OpioidOpioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioid use disorder, reversing opioid overdose, and suppressing cough. Extremely potent opioids such as carfentanil are approved only for veterinary use. Opioids are also frequently used non-medically for their euphoric effects or to prevent withdrawal.
HeroinHeroin, also known as diacetylmorphine and diamorphine among other names, is a morphinan opioid substance derived from the dried latex of the Papaver somniferum plant and is mainly used as a recreational drug for its euphoric effects. Medical-grade diamorphine is used as a pure hydrochloride salt. Various white and brown powders sold illegally around the world as heroin are routinely diluted with cutting agents.
CodeineCodeine is an opiate and prodrug of morphine mainly used to treat pain, coughing, and diarrhea. It is also commonly used as a recreational drug. It is found naturally in the sap of the opium poppy, Papaver somniferum. It is typically used to treat mild to moderate degrees of pain. Greater benefit may occur when combined with paracetamol (acetaminophen) or a nonsteroidal anti-inflammatory drug (NSAID) such as aspirin or ibuprofen. Evidence does not support its use for acute cough suppression in children or adults.
OxycodoneOxycodone, sold under various brand names such as Roxicodone and OxyContin (which is the extended release form), is a strong, semi-synthetic opioid used medically for treatment of moderate to severe pain. It is highly addictive and is a commonly abused drug. It is usually taken by mouth, and is available in immediate-release and controlled-release formulations. Onset of pain relief typically begins within fifteen minutes and lasts for up to six hours with the immediate-release formulation.
MorphineMorphine is a strong opiate that is found naturally in opium, a dark brown resin produced by drying the latex of opium poppies (Papaver somniferum). It is mainly used as a pain medication, and is also commonly used recreationally, or to make other illicit opioids. There are numerous methods used to administer morphine: oral; sublingual; via inhalation; injection into a muscle, injection under the skin, or injection into the spinal cord area; transdermal; or via rectal suppository.
KetamineKetamine is a dissociative anesthetic used medically for induction and maintenance of anesthesia. It is also used as a treatment for depression, a pain management tool, and as a recreational drug. Ketamine is a novel compound that was derived from phencyclidine in 1962, in pursuit of a safer anesthetic with fewer hallucinogenic effects. At anesthetic doses, ketamine induces a state of "dissociative anesthesia", a trance-like state providing pain relief, sedation, and amnesia.
DextromethorphanDextromethorphan (DXM) is a cough suppressant in over-the-counter cold and cough medicines. It affects NMDA, glutamate-1, and sigma-1 receptors in the brain, all of which have been implicated in the pathophysiology of depression. In 2022, the FDA approved a formulation of it combined with bupropion named Auvelity to serve as a rapid acting antidepressant in patients with major depressive disorder. It is sold in syrup, instant release tablet, extended release tablet, spray, and lozenge forms.
AddictionAddiction is generally a neuropsychological disorder defining pervasive and intense urge to engage in maladaptive behaviors providing immediate sensory rewards (e.g. consuming drugs, excessively gambling), despite their harmful consequences. Dependence is generally an addiction that can involve withdrawal issues. Addictive disorder is a category of mental disorders defining important intensities of addictions or dependences, which induce functional disabilities. There are no agreed definitions on these terms – see section on 'definitions'.
NeurotransmitterA neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotransmitters are released from synaptic vesicles into the synaptic cleft where they are able to interact with neurotransmitter receptors on the target cell. The neurotransmitter's effect on the target cell is determined by the receptor it binds to.
BenzodiazepineBenzodiazepines (BZD, BDZ, BZs), colloquially called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, insomnia, and seizures. The first benzodiazepine, chlordiazepoxide (Librium), was discovered accidentally by Leo Sternbach in 1955 and was made available in 1960 by Hoffmann–La Roche, who soon followed with diazepam (Valium) in 1963.