Effect of Ketanserin After LSD Administration (L-Ket)

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

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.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Drug: Lysergic Acid Diethylamide; Drug: Ketanserin Placebo; Drug: Ketanserin

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.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Phase 1

Contacts and Locations

Study Locations

• Switzerland
  • Basel, Switzerland, 4031
    • Clinical Pharmacology & Toxicology, University Hospital Basel

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 23 years to 63 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Age between 25 and 65 years old
2. Sufficient understanding of the German language
3. Understanding of procedures and risks associated with the study
4. Willing to adhere to the protocol and signing of the consent form
5. Willing to refrain from the consumption of illicit psychoactive substances during the study
6. Abstaining from xanthine-based liquids and foods from the evenings prior to the study sessions to the end of the study days
7. Willing not to operate heavy machinery within 48 hours after substance administration
8. Willing to use double-barrier birth control throughout study participation
9. Body mass index between 18-29 kg/m2

Exclusion Criteria:

1. Chronic or acute medical condition
2. Current or previous major psychiatric disorder
3. Psychotic disorder or bipolar disorder in first-degree relatives
4. Hypertension (>140/90 mmHg) or hypotension (SBP<85 mmHg)
5. Hallucinogenic substance use (not including cannabis) more than 20 times or any time within the previous two months
6. Pregnancy or current breastfeeding
7. Participation in another clinical trial (currently or within the last 30 days)
8. Use of medication that may interfere with the effects of the study medication
9. Tobacco smoking (>10 cigarettes/day)
10. Consumption of alcoholic beverages (>20 drinks/week)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 100 μg LSD + Ketanserin placebo	Drug: Lysergic Acid Diethylamide; A moderate dose of 100 μg LSD will be administered.; Other Names: LSD; Drug: Ketanserin Placebo; Mannitol capsules instead of capsules containing Ketanserin.
Experimental: 100 μg LSD + Ketanserin (40mg)	Drug: Lysergic Acid Diethylamide; A moderate dose of 100 μg LSD will be administered.; Other Names: LSD; Drug: Ketanserin; A dose of 40 mg Ketanserin will be administered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of subjective response	Visual Analog Scales (VAS) will be repeatedly used to assess subjective alterations in consciousness over time. VAS will be presented as 100 mm long horizontal lines marked with "not at all" on the left and "extremely" on the right. The following VAS will be used: "any effect", "good effect", "bad effect", "fear", "stimulated", "nausea", "tiredness", "alteration of hearing", "alteration of vision", "synesthesia", "alteration in sense of time", "the boundaries between myself and my surroundings seemed to blur", "talkative", "open", "trust" and "my focus is directed: outward/inward". Subjects will mark the scale with vertical lines.	12 months
Extent of subjective response	Visual Analog Scales (VAS) will be repeatedly used to assess subjective alterations in consciousness over time. VAS will be presented as 100 mm long horizontal lines marked with "not at all" on the left and "extremely" on the right. The following VAS will be used: "any effect", "good effect", "bad effect", "fear", "stimulated", "nausea", "tiredness", "alteration of hearing", "alteration of vision", "synesthesia", "alteration in sense of time", "the boundaries between myself and my surroundings seemed to blur", "talkative", "open", "trust" and "my focus is directed: outward/inward". Subjects will mark the scale with vertical lines.	12 months
Plasma concentrations of LSD	LSD plasma concentrations will be measured repeatedly over time using LC-MS/MS techniques (nanogram per milliliter scale).	12 months
Plasma concentrations of Ketanserin	LSD plasma concentrations will be measured repeatedly over time using Liquid chromatography-mass spectrometry (LC-MS)/MS techniques (nanogram per milliliter scale).	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
5 dimensions of altered state of consciousness (5D-ASC) profile total score	Visual analog scale consisting of 94 items. Constructed of five scales and allows assessing mood, anxiety, derealization, depersonalization, changes in perception, auditory alterations, and reduced vigilance. Scales will be presented as 100 mm long horizontal lines marked with vertical lines by the participant.	12 months
Adjective mood rating scale (AMRS)	The adjective mood rating scale (AMRS or EWL60S) is a 60-item 4-point Likert scale ("not at all", "somewhat", "rather", "strongly") that allows repeated assessment of mood in 6 dimensions: activation, inactivation, well-being, anxiety/depressed mood, extroversion and introversion, and emotional excitability.The AMRS consists of subscales measuring "activation", "positive mood", "extroversion", "introversion", "inactivation", and "emotional excitability".	12 months
States of consciousness questionnaire (SCQ)	This 100-item questionnaire is rated on a 6-point scale (0=none, not at all; 1=so slight cannot decide; 2=slight; 3=moderate; 4=strong (equivalent in degree to any previous strong experience or expectation of this description); 5=extreme (more than ever before in my life and stronger than 4)). Forty-three items embedded into this questionnaire comprise the Mystical Experience Questionnaire (MEQ). The 43 items provide scale scores for each of seven domains of mystical experiences: internal unity (pure awareness, a merging with ultimate reality), external unity (unity of all things, all things are alive, all is one), sense of sacredness (reverence, sacred), noetic quality (encounter with ultimate reality, more real than everyday reality), transcendence of time and space, deeply felt positive mood (joy, peace, love), paradoxicality/ineffability (claim of difficulty in describing the experience in words).	12 months
Blood pressure	Repeatedly measured using blood pressure / pulse apparatus (mmHg scale).	12 months
Heart rate	Repeatedly measured using blood pressure / pulse apparatus (beats per minute scale).	12 months
Body temperature	Repeatedly measured using ear thermometer (degree Celsius scale).	12 months
Pupil diameter	Repeatedly measured using pupil distance meter (millimeter scale).	12 months
Elliot Humility Scale (EHS)	Assesses the personality trait humility through 13 items on a 5-point Likert scale ranging from "strongly disagree" to "strongly agree".	12 months
Jankowski Humility Scale (JHS)	Assesses the personality trait humility through 18 items on a 5-point Likert scale ranging from "not at all" to "strongly".	12 months
Arnett Inventory of Sensation Seeking (AISS-d)	Assesses the personality trait of sensation seeking, which is is defined as a need for novel and intense stimulation. It uses 20 items using 4-point scales (1 = "describes me very well" to 4 = "does not describe me at all").	12 months
Freiburger Persönlichkeitsinventar (FPI)	The FPI-R version comprises 138 items and covers 12 dimensions of personality: life satisfaction, social orientation, performance orientation, inhibition, excitability, aggressiveness, stress, physical complaints, health concerns, openness, as well as the secondary factors according to Eysenck's Extraversion and Emotionality (Neuroticism). It uses a 2-point scale ("true" and "not true").	12 months
Saarbrücker Persönlichkeitsfragebogen (SPF)	The SPF defines empathy as the "reactions of one individual to the observed experiences of another." It assesses 28-items on a 5-point Likert scale ranging from "Does not describe me well" to "Describes me very well". The measure has 4 subscales (Perspective Taking, Fantasy, Empathic Concern, Personal Distress) each made up of 7 different items.	12 months
Defense Style Questionnaire (DSQ-40)	The DSQ-40 can provide scores for 20 individual defenses, and scores for the three factors "mature", "neurotic", and "immature". Each item is evaluated on a scale from 1 to 9, where "1" indicates "completely disagree" and "9" indicates "fully agree".	12 months

Collaborators and Investigators

• Sponsor: University Hospital, Basel, Switzerland
• Investigators: Principal Investigator: Matthias E Liechti, Dr., MD, University Hospital, Basel, Switzerland

Study record dates

Study Major Dates

• Study Start (Actual): October 16, 2020
• Primary Completion (Actual): August 28, 2021
• Study Completion (Actual): September 29, 2021

Study Registration Dates

• First Submitted: August 25, 2020
• First Submitted That Met QC Criteria: September 21, 2020
• First Posted (Actual): September 22, 2020

Study Record Updates

• Last Update Posted (Actual): October 21, 2021
• Last Update Submitted That Met QC Criteria: October 20, 2021
• Last Verified: October 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Antihypertensive Agents; Platelet Aggregation Inhibitors; Psychotropic Drugs; Serotonin Agents; Serotonin Receptor Agonists; Serotonin Antagonists; Hallucinogens; Ketanserin; Lysergic Acid Diethylamide
• Other Study ID Numbers: BASEC 2020-00614

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No