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Robert Kronstrand

4 papers in the library · 27 citations · publishing 2017-2026

Papers

In vitro characterization of new psychoactive substances at the μ-opioid, CB1, 5HT1A, and 5-HT2A receptors—On-target receptor potency and efficacy, and off-target effects

Forensic Science International October 23, 2020 Anna Åstrand, Davide Guerrieri, Svante Vikingsson et al. 21 citations

Sixty new psychoactive substances (NPS) and their metabolites, including opioids, cannabinoids, and serotonergic hallucinogens, were screened for their ability to activate μ-opioid, CB1, 5-HT1A, and 5-HT2A receptors. Most substances activated their intended target receptor. Among μ-opioid agonists, 2-fluorofentanyl (EC50 = 1.0 nM), carfentanil (EC50 = 2.7 nM), and acrylfentanyl (EC50 = 2.8 nM) were the most potent, with a >1500-fold potency range across compounds. Furanylfentanyl, 4-methoxybutyrylfentanyl, and valerylfentanyl acted as partial agonists. On the 5-HT2A receptor, bromo-dragonfly was the most potent (EC50 = 0.05 nM, 400 times more potent than LSD), followed by NBOMe compounds (EC50 0.11–1.3 nM). Off-target μ-opioid activation occurred for piperazines, phenethylamines, and tryptamines. The synthetic cannabinoid metabolite 3-carboxy indole PB-22 activated 5-HT2A. Bromo-dragonfly activated all four receptors. These findings highlight complex, often overlapping targets among NPS.

Epidemiology of New Psychoactive Substances in Relation to Traditional Drugs of Abuse in Clinical Oral Fluid Samples.

Basic & clinical pharmacology & toxicology February 1, 2025 Magnus A B Axelsson, Hanna Lövgren, Robert Kronstrand et al. 6 citations

New psychoactive substances (NPS) are a health hazard due to unpredictable toxicity and unknown prevalence. Analyzing 34,183 oral fluid samples from 9,468 psychiatric and addiction care patients in a Swedish region during 2019–2020, 58 different NPS were detected in 481 samples from 201 patients, totaling 618 findings. NPS use was more common in males and patients aged 25 or older. Ketamine use was associated with most NPS classes except cannabinoids; fentanyl, methadone, tapentadol, and clonazepam also correlated with multiple NPS classes. More traditional drugs of abuse correlated with sedative/hypnotic NPS, suggesting broader use. Mitragynine correlated negatively with other NPS but positively with opioid abstinence remedies buprenorphine, loperamide, and tapentadol, indicating its use for opioid withdrawal.

Comprehensive in vitro profiling of traditional and emerging stimulants at monoamine transporters and the 5-HT2A receptor.

British journal of pharmacology July 14, 2026 Darta Stalberga, Robert Kronstrand, Bianca Schranz et al.

Synthetic cathinones, a large class of new psychoactive substances, primarily inhibit dopamine, norepinephrine, and serotonin transporters, with high dopamine transporter selectivity linked to abuse potential. In vitro testing of 58 substances showed that N-pyrrolidine cathinones combined with methylenedioxy groups—MDPiHP, MDPEP, and MDPV—had the highest potency at the dopamine transporter. Other N-pyrrolidine cathinones, such as 3F-α-PHP, 3F-α-PiHP, and 4F-α-PiHP, showed the greatest dopamine transporter selectivity relative to the serotonin transporter. Chloromethcathinone and methylmethcathinone compounds, like 3-CMC, displayed an amphetamine-like profile with comparable potency at dopamine and norepinephrine transporters. Some cathinones at high concentrations and phenethylamines at micromolar concentrations also activated the 5-HT2A receptor, while 2C-like arylcyclohexylamines targeted the receptor without transporter inhibition. The majority of compounds, especially N-pyrrolidine cathinones, suggest high abuse potential based on their dopamine transporter selectivity.

A non-fatal intoxication and seven deaths involving the dissociative drug 3-MeO-PCP.

Forensic science international June 1, 2017 Anna Johansson, Daniel Lindstedt, Markus Roman et al.

3-Methoxyphencyclidine (3-MeO-PCP), a phencyclidine analogue with anesthetic, analgesic, and hallucinogenic properties, appeared on the illicit drug market in 2011. This paper reports a non-fatal intoxication and seven deaths involving 3-MeO-PCP in Sweden from March 2014 to June 2016. The non-fatal case involved a 19-year-old male with drug problems and depression who presented awake but tachycardic, hypertensive, tachypnoeic, and catatonic, later developing fever, lactic acidosis, psychomotor agitation, and hallucinations; he fully recovered after 22 hours of intensive care. Blood concentrations of 3-MeO-PCP at admission were 0.14 μg/g, declining to 0.04 μg/g after 17 hours, with an estimated half-life of 11 hours.