Psilocybin

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 120(SRC), determined from a structure estimation method(2), indicates that psilocybine is expected to have high mobility in soil(SRC). Estimated pKa values for psilocybine are 1.3 (first phosphate oxygen), 6.5 (second phosphate oxygen), and 10.4 (tertiary amine)(3), indicating that this compound will exist primarily as a zwitterion in the environment. Volatilization of psilocybine from moist soil surfaces is not expected to be an important fate process(SRC) because ionic compounds do not volatilize. Psilocybine is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.9X10-12 mm Hg(SRC), determined from a fragment constant method(4). Biodegradation data were not available(SRC, 2005).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 120(SRC), determined from a structure estimation method(2), indicates that psilocybine is not expected to adsorb to suspended solids and sediment(SRC). Estimated pKa values for psilocybine are 1.3 (first phosphate oxygen), 6.5 (second phosphate oxygen), and 10.4 (tertiary amine)(3), indicating that this compound will exist primarily as a zwitterion in the environment. Volatilization from water surfaces is not expected since ionic compounds do not volatilize. According to a classification scheme(4), an estimated BCF of 1(SRC), from an estimated log Kow of 1(5) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data were not available(SRC, 2005).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), psilocybine, which has an estimated vapor pressure of 1.9X10-12 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase psilocybine may be removed from the air by wet or dry deposition(SRC). Psilocybine does absorb at wavelengths >290 nm(3) and therefore may be susceptible to direct photolysis by sunlight(SRC).

Psilocybin is rapidly dephosphorylated in the body to psilocin which then acts as a partial agonist at the 5-HT2A serotonin receptor in the brain where it mimics the effects of serotonin (5-HT). Psilocin is an 5-HT1A and 5-HT2A/2C agonist. (L1143)

Initially the subject may begin to feel somewhat disoriented, lethargic, and euphoric or sometimes depressed. At low doses, hallucinatory effects may occur, including enhancement of colors and the animation of geometric shapes. Closed-eye hallucination may occur, where the affected individual may see multi-coloured geometric shapes and vivid imaginative sequences. At higher doses, hallucinatory effects increase and experiences tend to be less social and more introspective or entheogenic. Open-eye visuals are more common, and may be very detailed although rarely confused with reality. (L1143)

Using a structure estimation method based on molecular connectivity indices(1), the Koc of psilocybine can be estimated to be 120(SRC). According to a classification scheme(2), this estimated Koc value suggests that psilocybine is expected to have high mobility in soil. Estimated pKa values for psilocybine are 1.3 (first phosphate oxygen), 6.5 (second phosphate oxygen), and 10.4 (tertiary amine)(3), indicating that this compound will exist primarily as a zwitterion in the environment.

/SIGNS AND SYMPTOMS/ Mydriasis and blurred vison are common, but other sympathomimetic signs, such as tachycardia, hypertension, and hyperreflexia, are seen in less than one-half of emergency department patients. Dysphoria, disorientation, ataxia, agitation, and aggressive behavior may appear after ingestions. Antisocial behavior represents the greatest danger to life. Hallucinations occur in less than one-half of patients who ingest these mushrooms. Visual hallucinations are more common than auditory hallucinations; however, alterations in perception occur in almost all patients and involve primarily distortion of shapes and colors. /Hallucinogenic mushrooms/

/SIGNS AND SYMPTOMS/ Patients typically present with dysphoric and sympathomimetic symptoms that are transient, lasting less than 12 hours. The adolescent substance abuser when seen in a state of panic may have ingested hallucinogenic mushrooms possibly with simultaneous lysergic acid diethylamide (LSD), alcohol, phencyclidine, and marijuana. The potential for self-inflicted or accidental trauma during periods of altered behavior represents the greatest health hazard, although persistent psychiatric symptoms have been rarely reported. /Hallucinogenic mushrooms/

/SIGNS AND SYMPTOMS/ Agitation and hallucination were reported after ingestion of ten mushrooms in one case; however, another patient complained of only abdominal pain after consuming 200 mushrooms. /Hallucinogenic mushrooms/

/SIGNS AND SYMPTOMS/ Patients usually present within 4 hours of ingestion with symptoms of lightheadedness, weakness, and anxiety that began 30 to 60 minutes after ingestion. Most symptoms resolve within 4 hours, and persistence of dysphoric symptoms past 12 hours is rare. Persistent neurologic symptoms comprised primarily of flashback phenomena are well recognized but are uncommon complications of psilocybin ingestion.

For more Human Toxicity Excerpts (Complete) data for PSILOCYBINE (9 total), please visit the HSDB record page.

An estimated BCF of 1 was calculated for psilocybine(SRC), using an estimated log Kow of 1(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

Estimated pKa values for psilocybine are 1.3 (first phosphate oxygen), 6.5 (second phosphate oxygen), and 10.4 (tertiary amine)(1), indicating that this compound will exist primarily as a zwitterion in the environment. Psilocybine is expected to be essentially nonvolatile from moist soil and water surfaces since ionic compounds do not volatilize.

Schedules of controlled substances are established by section 202 of the Controlled Substances Act (21 U.S.C. 812). Schedule I shall consist of the drugs and other substances, by whatever official name, common or usual name, chemical name, or brand name designated, listed in this section. Unless specifically excepted or unless listed in another schedule, any material, compound, mixture, or preparation, which contains any quantity of the following hallucinogenic substances, or which contains any of its salts, isomers, and salts of isomers whenever the existence of such salts, isomers, and salts of isomers is possible within the specific chemical designation (for purposes of this paragraph only, the term "isomer" includes the optical, position and geometric isomers): DEA Code #: 7437; Drug class: hallucinogenic substances.

The major hallucinogenic constituent of the sacred Mexican mushroom Teonanacatl; A controlled substance and psychomimetic; [Merck Index] Alkaloid found in certain mushrooms; [Hawley]

Hallucinogens

The use of hallucinogenic mushrooms predates the arrival of the Spaniards to the New World. The Aztecs consumed a substance called teonanacatl (God's flesh) in religious ceremonies. Later, Psilocybe mexicana was discovered to be the active component of teonanacatl. The use of mushrooms by people native to the Americas to produce mystical revelations during religious ceremonies continued into the twentieth century.

Psilocybin has no recognized medical uses. However, it has been investigated as an experimental treatment for several disorders. (L1143)