AzTrials
AzTrials

HealthyPhase 1L-KetNCT04558294

Effect of Ketanserin After LSD Administration

A Phase 1 study testing Lysergic Acid Diethylamide and Ketanserin in people with Healthy, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial 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. Read more about this study

Who is it for?
Ages 25 to 65 yearsHealthy volunteers can take part
Conditions the study is for
Healthy
What is being tested?
Lysergic Acid Diethylamide and Ketanserin
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
24 participants
Where
1 siteSwitzerland
Study dates
16 Oct 2020to 29 Sep 2021
Phase
Phase 1
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 25 to 65 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

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

Who cannot join

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

Trial locations and contacts

1 site in 1 country.

Switzerland1 site

  • Clinical Pharmacology & Toxicology, University Hospital Basel

    Basel, 4031

Other trials in Switzerland

About this study

Official title: 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.

Read the 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
Being tested
Lysergic Acid Diethylamide, Ketanserin Placebo, Ketanserin

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Lysergic Acid DiethylamideDrug

    Also called LSD

    A moderate dose of 100 μg LSD will be administered.

  • Ketanserin PlaceboDrug

    Mannitol capsules instead of capsules containing Ketanserin.

  • KetanserinDrug

    A dose of 40 mg Ketanserin will be administered.

Study groups in NCT04558294
Study groupRoleWhat they receive
100 μg LSD + Ketanserin placeboExperimentalNot described
Receives: Drug: Lysergic Acid Diethylamide; Drug: Ketanserin Placebo
100 μg LSD + Ketanserin (40mg)ExperimentalNot described
Receives: Drug: Lysergic Acid Diethylamide; Drug: Ketanserin

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. 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.

    Measured: 12 months

  2. 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.

    Measured: 12 months

  3. Plasma concentrations of LSD

    LSD plasma concentrations will be measured repeatedly over time using LC-MS/MS techniques (nanogram per milliliter scale).

    Measured: 12 months

  4. 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).

    Measured: 12 months

Secondary outcomes (13)

  1. 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.

    Measured: 12 months

  2. 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".

    Measured: 12 months

  3. 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).

    Measured: 12 months

  4. Blood pressure

    Repeatedly measured using blood pressure / pulse apparatus (mmHg scale).

    Measured: 12 months

  5. Heart rate

    Repeatedly measured using blood pressure / pulse apparatus (beats per minute scale).

    Measured: 12 months

  6. Body temperature

    Repeatedly measured using ear thermometer (degree Celsius scale).

    Measured: 12 months

  7. Pupil diameter

    Repeatedly measured using pupil distance meter (millimeter scale).

    Measured: 12 months

  8. 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".

    Measured: 12 months

  9. 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".

    Measured: 12 months

  10. 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").

    Measured: 12 months

  11. 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").

    Measured: 12 months

  12. 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.

    Measured: 12 months

  13. 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".

    Measured: 12 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted22 Sep 2020
  2. Study start16 Oct 2020
  3. Primary completion28 Aug 2021
  4. Study completion29 Sep 2021

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Model description
Double-blind, placebo-controlled, random-order 2-period cross-over design with 2 treatment conditions: 1. 100 μg LSD + ketanserin (40 mg) 2. 100 μg LSD + placebo
Masking
Triple blind
Who is masked
Participant, Care provider, Investigator
Enrolment
24 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04558294
Sponsor's protocol ID
BASEC 2020-00614
Acronym
L-Ket
Status last verified
Oct 2021
First submitted
25 Aug 2020
Last updated
21 Oct 2021
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Becker AM, Klaiber A, Holze F, Istampoulouoglou I, Duthaler U, Varghese N, Eckert A, Liechti ME. Ketanserin Reverses the Acute Response to LSD in a Randomized, Double-Blind, Placebo-Controlled, Crossover Study in Healthy Participants. Int J Neuropsychopharmacol. 2023 Feb 14;26(2):97-106. doi: 10.1093/ijnp/pyac075.

    PubMed 36342343

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing Lysergic Acid Diethylamide and Ketanserin in people with Healthy, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 21 Oct 2021. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Duration of subjective response (time frame: 12 months). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04558294, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Oct 2021.

AzTrials uses cookies for analytics and advertising. You can accept or reject them; the site works either way. Privacy Policy.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in