Also called:
delta-8-tetrahydrocannabinol

delta-8-THC, naturally occurring chemical compound found in cannabis plants, namely the species Cannabis indica and C. sativa, which are sources of hemp and marijuana. Delta-8-tetrahydrocannabinol (THC) is chemically related to delta-9-THC, which is the primary psychoactive compound in cannabis products; delta-8-THC, however, has milder psychoactive effects. Delta-8-THC is thought to have some potential therapeutic benefits, though a lack of scientific evidence and regulatory oversight has raised concerns about safety and quality.

Delta-8-THC is so-named for the location of a double bond that occurs on the eighth carbon atom in its molecular carbon chain structure. The location of this bond is significant, since it not only is used to define the different types of THC but also affects the interaction of THC molecules with cellular receptors. Within cannabis plants, only very small amounts of delta-8-THC are produced, far less than delta-9-THC. Semisynthetic delta-8-THC can be produced from cannabidiol (CBD) that has been extracted from hemp or generated via isomerization of delta-9-THC. In general, delta-8-THC is more easily synthesized than delta-9-THC and its semisynthetic forms are more stable. Semisynthetic delta-8-THC is used in products such as capsules, gummies, vape cartridges, and tinctures. Because it has only partial efficacy at cannabinoid receptors, it is less potent than many synthetic cannabinoids.

Anecdotal reports suggest that delta-8-THC possesses potential health benefits. For example, some persons believe that the substance can reduce nausea, relieve chronic pain, and help reduce anxiety. Evidence for these claims, however, is largely lacking. Moreover, similar to other cannabinoids, delta-8-THC can cause side effects, including dry mouth, drowsiness, and fatigue. It also can impair coordination and judgment and increase anxiety. In addition, many delta-8-THC products are not tested for purity or safety, and research indicates that such products vary in cannabinoid content and potency. In fact, many products sold as delta-8-THC do not actually contain the compound in pure form and are contaminated with other cannabinoids, including delta-9-THC and chemically related substances not known to occur naturally. Various reaction by-products have also been detected in delta-8-THC products. These factors have raised significant concerns about product safety.

In addition, the legal status of delta-8-THC is complex. In the United States, for example, under the Agriculture Improvement Act of 2018, hemp-derived products with less than 0.3 percent THC are not controlled substances. However, because delta-8-THC is sometimes considered a type of synthetic cannabinoid, its legality is questioned and potentially subject to federal restrictions. Moreover, state laws differ, with some states allowing and others banning delta-8-THC. The legality of delta-8-THC is similarly ambiguous in other countries, particularly those of the European Union. Other countries have relatively clear laws, such as in Canada, where delta-8-THC is regulated as a controlled substance under the Cannabis Act.

Kara Rogers
Also called:
2-(2-chlorophenyl)-2-(methylamino)-cyclohexanone or CI581

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ketamine, general anesthetic agent related structurally to the hallucinogen phencyclidine (PCP). Ketamine was first synthesized in 1962 at Parke Davis Laboratories by American scientist Calvin Stevens, who was searching for a new anesthetic to replace PCP, which was not suitable for use in humans because of the severe hallucinogenic effects it produced upon recovery of consciousness. Ketamine was originally patented in Belgium in 1963 and was approved for use in humans by the U.S. Food and Drug Administration in 1970. Soon after, it was put to use to treat American soldiers fighting in the Vietnam War. Today, since ketamine can produce minor hallucinogenic side effects in humans, it is used most often as a veterinary anesthetic. However, the drug does have valuable applications in human medicine, especially as an anesthetic for children and for individuals undergoing minor surgery. It may also be used to treat depression and chronic pain.

Unlike inhalation anesthetics or sedative anesthetics (e.g., narcotics and benzodiazepines), ketamine does not depress respiration or other basic functions of the central nervous system. Thus, ketamine has a relatively wide margin of safety. In addition, it is distinct from other anesthetics because it has three major effects: analgesia (pain relief), hypnosis (sedation), and amnesia. The drug is known particularly for its ability to induce a dissociative (cataleptic) state, which is characterized by a lack of pain sensation, unconsciousness, and increased muscle tone. These characteristics are often accompanied by open eyes, jumping eye movements (nystagmus), and involuntary limb movements.

Ketamine works by altering the activity of neurons in the brain. This is accomplished through the drug’s inhibition of neuronal uptake of various neurotransmitters, including serotonin, glutamate, and dopamine. The net effect is a depression of neural communication between the thalamus and the cerebral cortex, resulting in an uncoupling of brain activity associated with memory, motor function, sensory experience, and emotion. Ketamine also stimulates activity in the limbic system, a region of the brain involved in controlling certain autonomic functions and in integrating various brain activities, including those associated with motivation and emotion.

In clinical use ketamine is administered intramuscularly or intravenously. Minor side effects of the drug include tearing (lacrimation) when emerging from the dissociative anesthetic state. Patients can sometimes experience severe and troubling hallucinogenic effects, such as intense dreams and delirium, upon waking; these effects are more common in adults than in children. Hallucinations are directly related to dose. Thus, higher doses produce more pronounced delirium and other symptoms of hallucination than do lower doses.

Ketamine’s ability to produce hallucinogenic effects within minutes after administration has led to its abuse as a recreational drug. The dissociative effect of ketamine that is produced by high doses is often described by recreational users as the “K hole”—a separation of the mind and body, or a hallucinatory “out of body” experience. Ketamine is known by various street names, including K, special K, jet, super acid, and cat valium. It may be snorted, injected, or taken orally, and its effects may last from 30 minutes to more than an hour. However, for one or more days after taking the drug, users may display symptoms of amnesia, schizophrenia, impaired judgment, and lack of coordination. In addition, long-term abuse can lead to paranoia, depression, and other evidence of cognitive dysfunction. Many individuals appear to be in a stupor when the drug has been taken in low doses; however, high doses can cause unconsciousness, cardiovascular depression, and death.

Kara Rogers