Diphenidine
Dissociative anesthetic designer drug
From Wikipedia, the free encyclopedia
Diphenidine (1,2-DEP, DPD, DND) is a dissociative anesthetic that has been sold as a designer drug.[2][3][4] Diphenidine was first synthesized in 1924 using a Bruylants reaction similar to the one later employed in the discovery of phencyclidine in 1956.[2] Following the 2013 UK ban on arylcyclohexylamines, diphenidine and the related compound methoxphenidine emerged on the grey market.[2] Anecdotal reports indicate that high doses of diphenidine can produce "bizarre somatosensory phenomena and transient anterograde amnesia."[2]
- AU: S9 (Prohibited substance)
- BR: Class F2 (Prohibited psychotropics)[1]
- CA: Schedule I
- DE: Anlage II (Authorized trade only, not prescriptible)
- UK: Under Psychoactive Substances Act
- UN: Psychotropic Schedule II
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| Formula | C19H23N |
| Molar mass | 265.400 g·mol−1 |
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| Melting point | 210 °C (410 °F) |
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Pharmacology
Electrophysiological studies show that diphenidine reduces the amplitude of NMDA-mediated fEPSPs to a similar extent as ketamine, although its antagonistic effect has a slower onset.[5] The drug's two enantiomers exhibit markedly different NMDA receptor affinities, with the (S)-enantiomer being approximately 40 times more potent than the (R)-enantiomer.[6] Since diphenidine's emergence in 2013, vendors have claimed it acts on the dopamine transporter, but supporting data only became available in 2016.[2] While diphenidine shows the highest affinity for the NMDA receptor, it also binds with submicromolar affinity to the σ1 receptor, σ2 receptor, and dopamine transporter.[7][8]
Research
Diphenidine and other diarylethylamines have been studied in vitro for their potential in treating neurotoxic injury. These compounds act as antagonists at the NMDA receptor.[9][6][5][10][11] In dogs, diphenidine demonstrates greater antitussive potency than codeine phosphate.[12][13]
Illicit use
Since 2014, diphenidine has been detected in combination with other research chemicals, particularly synthetic cannabinoids and stimulants, in Japanese herbal incense blends.[14][15][16] The first reported seizure involved a Japanese product labeled as "fragrance powder," which contained both diphenidine and benzylpiperazine[17] A herbal incense product called "Aladdin Spacial [sic] Edition," sold in Shizuoka Prefecture, was found to contain 289 mg/g of diphenidine and 55.5 mg/g of 5F-AB-PINACA.[14] Another product, Herbal Incense. The Super Lemon, containing AB-CHMINACA, 5F-AMB, and diphenidine, was linked to a fatal poisoning.[15] More recently, diphenidine was implicated in a fatal case involving the simultaneous use of three substituted cathinones, three benzodiazepines, and alcohol, consumed through "bath salt" and "liquid aroma" products in Japan.[18]
In Canada, MT-45 and its analogues—including DPD—were added to Schedule I controlled substances in 2016.[19] Possession without proper authorization may result in a maximum penalty of seven years' imprisonment. That same year, Health Canada amended the Food and Drug Regulations to explicitly classify DPD as a restricted drug. Possession is limited to law enforcement agencies, individuals with exemption permits, or institutions with ministerial authorization.