NCT04558294

Effect of Ketanserin After LSD Administration

Effect of Ketanserin After LSD Administration on the Acute Response to LSD in Healthy Subjects

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 24 (actual)
• Sponsor: University Hospital, Basel, Switzerland · Academic / Other
• Sex: All
• Age: 25 Years – 65 Years
• Healthy volunteers: Accepted

Summary

LSD (lysergic acid diethylamide) is a serotonergic (5-HT) hallucinogen widely used for recreational and/or ethnomedical purposes. LSD is thought to induce its prototypical psychedelic effects primarily via stimulation of the 5-HT2A receptor. This study investigates whether an LSD experience can be attenuated and shortened using 5-HT2A receptor antagonist ketanserin administration after LSD once the psychedelic effects have established.

Detailed description

LSD is a so-called "classic" or serotonergic hallucinogen or psychedelic.The effects of LSD have been frequently investigated in the past in both healthy participants and patients. In these studies, LSD produced acute transient alterations in waking consciousness including visual perceptual alterations, audio-visual synesthesia, derealization and depersonalization. Moreover, several of these studies described robust and sustained effects of LSD in patients suffering from addiction, anxiety and depression. Its psychedelic effects are mainly attributed to its potent partial 5-HT2A receptor agonism. Consistently, administration the 5-HT2A receptor antagonist ketanserin (40 mg) prior to the administration of LSD (100 μg) almost completely prevented the acute effects of LSD in another study of our research group (NCT03321136). The present study hypothesis is that ketanserin (40 mg) administered 1h after LSD shortens and reduces the acute subjective effects of LSD (100 μg) compared to LSD alone (100 μg) followed by placebo in healthy humans. Such a finding would confirm a primarily competitive antagonism of ketanserin and LSD at the 5-HT2A receptor in vivo and indicate that LSD produces its psychedelic effects only when present at the receptor.

Conditions

• Healthy

Interventions

Type	Name	Description
DRUG	Lysergic Acid Diethylamide	A moderate dose of 100 μg LSD will be administered.
DRUG	Ketanserin Placebo	Mannitol capsules instead of capsules containing Ketanserin.
DRUG	Ketanserin	A dose of 40 mg Ketanserin will be administered.

Timeline

• Start date: 2020-10-16
• Primary completion: 2021-08-28
• Completion: 2021-09-29
• First posted: 2020-09-22
• Last updated: 2021-10-21

Locations

1 site across 1 country: Switzerland