title: Cytochrome P450 inhibition potential of new psychoactive substances of the tryptamine class.
abstract: New psychoactive substances (NPS) are not tested for their cytochrome P450 (CYP) inhibition potential before consumption. Therefore, this potential was explored for tryptamine-derived NPS (TDNPS) including alpha-methyl tryptamines (AMTs), dimethyl tryptamines (DMTs), diallyl tryptamines (DALTs), and diisopropyl tryptamines (DiPTs) using test substrates preferred by the Food and Drug Administration in a cocktail assay. All tested TDNPS with the exception of DMT inhibited CYP2D6 activity with IC50 values below 100μM. DALTs inhibited CYP2D6 activity similar to paroxetine and quinidine and CYP1A2 activity comparable to fluvoxamine. 5-Methoxy-N,N-diallyltryptamine reduced in vivo the caffeine metabolism in rats consistent with in vitro results. Five of the AMTs also inhibited CYP1A2 activity comparable to amiodarone. AMT and 6-F-AMT inhibited CYP2A6 activity in the range of the test inhibitor tranylcypromine. CYP2B6 activity was inhibited by 19 tryptamines, but weakly compared to efavirenz. CYP2C8 activity was inhibited by five of the tested TDNPS and three showed values comparable to trimethoprim and gemfibrozil. Six tryptamines inhibited CYP2C9 and seven CYP2C19 activities comparable to fluconazole and chloramphenicol, respectively. Nineteen compounds showed inhibition of CYP2E1 and 18 of CYP3A activity, respectively. These results showed that the CYP inhibition by TDNPS might be clinically relevant, but clinical studies are needed to explore this further.
authors.affiliation: Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, D-66421 Homburg (Saar), Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Dinger
authors.affiliation: School of Pharmacy & Biomolecular Sciences, John Moores University, Liverpool, UK.
authors.forename: Campbell
authors.initials: C
authors.lastname: Woods
authors.affiliation: School of Pharmacy & Biomolecular Sciences, John Moores University, Liverpool, UK.
authors.forename: Simon D
authors.initials: SD
authors.lastname: Brandt
authors.affiliation: Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, D-66421 Homburg (Saar), Germany; Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden.
authors.forename: Markus R
authors.initials: MR
authors.lastname: Meyer
authors.affiliation: Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, D-66421 Homburg (Saar), Germany. Electronic address: hans.maurer@uks.eu.
authors.forename: Hans H
authors.initials: HH
authors.lastname: Maurer
mesh_terms: D000818:Animals; D002110:Caffeine / Q000737:chemistry / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000737:chemistry / Q000494:pharmacology; D065607:Cytochrome P-450 Enzyme Inhibitors / Q000494:pharmacology*; D004347:Drug Interactions; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D008297:Male; D011619:Psychotropic Drugs / Q000494:pharmacology*; D051381:Rats; D013329:Structure-Activity Relationship; D014363:Tryptamines / Q000494:pharmacology*
chemical_list: D000697:Central Nervous System Stimulants; D065607:Cytochrome P-450 Enzyme Inhibitors; D007527:Isoenzymes; D011619:Psychotropic Drugs; D014363:Tryptamines; D002110:Caffeine
keywords: CYP inhibition; Cocktail assay; Tryptamine-derived new psychoactive substance