Cocaine Use Disorder (CUD)POTCHICUDNCT07532460
The Role of Potassium Channels in Working Memory Impairments of Chronic Cocaine Users
A study testing 4-aminopyridine (4-AP) in people with Cocaine Use Disorder (CUD) and Cognitive Impairments, run by Boris Quednow at 1 site in Switzerland.
Trial summary
The study aims to address the neurobiological basis of cognitive impairments in chronic cocaine users by investigating the potential impact of an acute potassium channel blockade on working memory performance and other cognitive functions. Read more about this study
- Who is it for?
- Ages 20 to 50 years
- Conditions the study is for
- Cocaine Use Disorder (CUD), Cognitive Impairments
- What is being tested?
- 4-aminopyridine (4-AP)
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 40 participants
- Where
- 1 siteSwitzerland
- Study dates
- 28 May 2026to Aug 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 20 to 50 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Current diagnosis of mild, moderate, or severe CoUD according to DSM-5
- Minimum cocaine use of 1g/month in the last three months
- Cocaine as the primary drug of consumption
- Willingness to abstain from cocaine use at least 72 hours before prior to each study visit
- Ability to read, understand and provide written informed consent
- To be sufficiently fluent in German
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- Age between 20 and 50 years
- Body mass index (BMI) between 19 and 30 kg/m2
- If applicable: luteal phase of the menstrual cycle
- For individuals with childbearing potential: use of contraceptive measures
Who cannot join
- Presence or history of severe neurological disorders or head injuries
- Current diagnosis of an acute or chronic infectious disease
- If applicable: pregnancy and breastfeeding
- Lifetime history of any epileptic seizures
- Lifetime diagnosis of a cardiovascular disease, specifically arrhythmia and long QT syndrome
- Clinically significant laboratory or ECG abnormality that could be a safety issue in the study
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- Lifetime diagnosis of liver or kidney disease including moderate or severe renal impairment (creatinine clearance < 50 ml/min)
- Known hypersensitivity or allergy to 4-aminopyridine
- Use of potassium channel blockers within the last 3 months
- Use of psychotropic medication within the last 7 days
- Use of inhibitors of the organic cation transporter 2 (OCT2), such as cimetidine
- Lifetime diagnosis of schizophrenia, bipolar disorder, obsessive-compulsive disorder, or autism spectrum disorder according to DSM-5
- Diagnosis of a current episode of depression
- Current diagnosis of a moderate or severe substance use disorder other than CoUD according than DSM-5
- Daily cannabis consumption in the past three months
- (E-Cigarette) Fagerström Test of Nicotine Dependence Score > 5 (strong nicotine dependence)
- Inability to follow the procedures of the study, e.g., due to language problems
- Being related to or in any form dependent on the investigator
- Prior participation (less than two years ago) in a study investigating working memory using the n-back task, the SWM, PAL, RVP, or LNST
- Participation in another study with investigational drugs within the 30 days preceding and during the present study
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Switzerland1 site, 1 recruiting
- Recruiting
University Hospital of Psychiatry Zurich
Zurich, Canton of Zurich, 8008
Prof. Dr. rer. nat. Boris B. Quednow, Dr. rer. nat., +41 58 384 27 77, quednow@bli.uzh.ch
Laura V. Schurek, M. Sc., +41 58 384 26 16, studie-potchicud@bli.uzh.ch
About this study
Official title: Randomised, Double-Blind, Placebo-Controlled, Crossover Study Investigating the Role of Potassium Channels in Working Memory Impairments of Chronic Cocaine Users
The study aims to address the neurobiological basis of cognitive impairments in chronic cocaine users by investigating the potential impact of an acute potassium channel blockade on working memory performance and other cognitive functions.
Read the detailed description
Chronic cocaine use is associated with impairments in cognitive functions, particularly in working memory, which are thought to contribute to the persistence of addictive behaviors and high relapse rates. Despite the clinical relevance of these cognitive deficits, the underlying neuropharmacological mechanisms remain insufficiently understood.
Preclinical and clinical evidence suggests that potassium channels may play an important role in the regulation of neuronal excitability and cognitive processes, including working memory. However, their contribution to cognitive impairments in individuals with cocaine use disorder has not yet been systematically investigated in humans.
The present study aims to investigate the role of potassium channel modulation in working memory performance in individuals with chronic cocaine use. The study addresses the following key research questions: (1) Does modulation of potassium channels influence working memory performance in individuals with chronic cocaine use? and (2) How are potential effects related to behavioral responses observed during the experimental sessions?
To address these questions, a randomized, controlled, cross-over study will be conducted in participants with a history of chronic cocaine use. Participants will complete a series of neurocognitive tasks assessing working memory and related cognitive domains under controlled experimental conditions. Blood samples will be collected at multiple time points to quantify substance levels and to support the interpretation of behavioral findings. The results of this study may contribute to a better understanding of the neurobiological mechanisms underlying cognitive impairments in cocaine use and inform future research on cognitive dysfunction in substance use disorders.
- Conditions
- Cocaine Use Disorder (CUD), Cognitive Impairments
- Being tested
- 4-aminopyridine (4-AP), Placebo
- Keywords
- cognitive impairments, cocaine use disorder, potassium channels, working memory, 4-aminopyridine, fampridine
- Medical subject headings
- Cognitive Dysfunction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
4-aminopyridine (4-AP)Drug
Two doses of fampridine administered during one of the two experimental test sessions.
PlaceboDrug
Matching placebo administered during one of the two experimental test sessions.
| Study group | Role | What they receive |
|---|---|---|
| Sequence AB | Experimental | Participants receive fampridine (A) in one experimental session and placebo (B) in the other, in the order A then B. Receives: Drug: 4-aminopyridine (4-AP); Drug: Placebo |
| Sequence BA | Experimental | Participants receive placebo (B) in one experimental session and fampridine (A) in the other, in the order B then A. Receives: Drug: 4-aminopyridine (4-AP); Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Global Working Memory Performance
Working memory performance will be assessed using a cognitive test battery covering different domains of working memory, including visuo-spatial (Spatial Working Memory [SWM], total errors; Paired Associates Learning [PAL], first trial memory score) and verbal-numeric components (Letter Number Sequencing Task [LNST], total score; Letter N-Back Task, discrimination index d'). Individual test scores will be standardized (z-transformation) and combined into a global working memory score according to Vonmoos et al (2013).
Measured: Baseline and during both experimental sessions
Secondary outcomes (5)
Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP)
Neurofilament light chain (NfL), a marker of axonal integrity, and glial fibrillary acidic protein (GFAP), a marker of microglia activation, levels will be analysed to assess potential drug challenge-related brain structural remodelling or to predict the effect of potassium challenge blockade.
Measured: Baseline and during both experimental sessions
Subjective ratings of current mood and craving
Subjective ratings of current mood (affective state, stress) and craving, pre- and post-cue exposure.
Current affective state will be assessed using the Positive and Negative Affect Schedule (PANAS; positive affect range: 10-50, negative affect range: 10-50) and visual analog scales (VAS; range 0-100, with higher scores indicating greater levels) of affective state and stress burden.
Current cocaine craving will be assessed using the Cocaine Craving Questionnaire-Brief (CCQ-Brief; total score range: 10-70, with higher scores representing worse outcomes) and visual analog scales (VAS; range 0-100, with higher scores indicating greater levels) of craving intensity, distinguishing between wanting, needing and having the urge for cocaine.
Measured: Baseline and during both experimental sessions
Adverse effects of the study drug
Potential adverse effects of the study drug will be assessed using the List of Complaints and visual analog scales (VAS; range 0-100, with higher scores indicating greater levels) of perceived effects of the substance, dizziness, drowsiness, nausea and impaired concentration.
Measured: During both experimental sessions
Plasma concentration
Plasma concentration of the study drug
Measured: During both experimental sessions
Heart rate variability
Heart rate variability is recorded during the test sessions to measure the level of stress and to investigate whether the physiological strain of the test is reduced when taking the study drug.
Measured: During both experimental sessions
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Apr 2026
- Study start28 May 2026
- Primary completionAug 2027 (estimated)
- Study completionAug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cocaine Use Disorder (CUD)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Boris Quednow
- Sponsor type
- University, hospital or other
- Collaborators
- University of Zurich
- Responsible party
- Sponsor-investigator, Boris Quednow, Psychiatric University Hospital, Zurich
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07532460
- Sponsor's protocol ID
- 2025-01432
- Other IDs
- 2025
- Acronym
- POTCHICUD
- Status last verified
- Aug 2026
- First submitted
- 8 Apr 2026
- Last updated
- 17 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomised, Double-Blind, Placebo-Controlled, Crossover Study Investigating the Role of Potassium Channels in Working Memory Impairments of Chronic Cocaine Users
- ClinicalTrials.gov ID
- NCT07532460
- Acronym / sponsor ID
- POTCHICUD / 2025-01432
- Conditions
- Cocaine Use Disorder (CUD), Cognitive Impairments
- Keywords
- cognitive impairments, cocaine use disorder, potassium channels, working memory, 4-aminopyridine, fampridine
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Boris QuednowUniversity, hospital or other
- Collaborators
- University of Zurich
- Study start
- 28 May 2026 (actual)
- Primary completion
- Aug 2027 (estimated)
- Study completion
- Aug 2027 (estimated)
- First posted
- 16 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The study aims to address the neurobiological basis of cognitive impairments in chronic cocaine users by investigating the potential impact of an acute potassium channel blockade on working memory performance and other cognitive functions.
Detailed description
Chronic cocaine use is associated with impairments in cognitive functions, particularly in working memory, which are thought to contribute to the persistence of addictive behaviors and high relapse rates. Despite the clinical relevance of these cognitive deficits, the underlying neuropharmacological mechanisms remain insufficiently understood.
Preclinical and clinical evidence suggests that potassium channels may play an important role in the regulation of neuronal excitability and cognitive processes, including working memory. However, their contribution to cognitive impairments in individuals with cocaine use disorder has not yet been systematically investigated in humans.
The present study aims to investigate the role of potassium channel modulation in working memory performance in individuals with chronic cocaine use. The study addresses the following key research questions: (1) Does modulation of potassium channels influence working memory performance in individuals with chronic cocaine use? and (2) How are potential effects related to behavioral responses observed during the experimental sessions?
To address these questions, a randomized, controlled, cross-over study will be conducted in participants with a history of chronic cocaine use. Participants will complete a series of neurocognitive tasks assessing working memory and related cognitive domains under controlled experimental conditions. Blood samples will be collected at multiple time points to quantify substance levels and to support the interpretation of behavioral findings. The results of this study may contribute to a better understanding of the neurobiological mechanisms underlying cognitive impairments in cocaine use and inform future research on cognitive dysfunction in substance use disorders.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Sequence AB | Experimental | Drug: 4-aminopyridine (4-AP), Drug: PlaceboParticipants receive fampridine (A) in one experimental session and placebo (B) in the other, in the order A then B. |
| Sequence BA | Experimental | Drug: 4-aminopyridine (4-AP), Drug: PlaceboParticipants receive placebo (B) in one experimental session and fampridine (A) in the other, in the order B then A. |
Who may qualify
- Ages
- 20 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (10 listed)
- Current diagnosis of mild, moderate, or severe CoUD according to DSM-5
- Minimum cocaine use of 1g/month in the last three months
- Cocaine as the primary drug of consumption
- Willingness to abstain from cocaine use at least 72 hours before prior to each study visit
- Ability to read, understand and provide written informed consent
Key exclusion criteria (20 listed)
- Presence or history of severe neurological disorders or head injuries
- Current diagnosis of an acute or chronic infectious disease
- If applicable: pregnancy and breastfeeding
- Lifetime history of any epileptic seizures
- Lifetime diagnosis of a cardiovascular disease, specifically arrhythmia and long QT syndrome
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 4-aminopyridine (4-AP)Two doses of fampridine administered during one of the two experimental test sessions. | Drug | Sequence AB, Sequence BA |
| PlaceboMatching placebo administered during one of the two experimental test sessions. | Drug | Sequence AB, Sequence BA |
Primary outcome
Global Working Memory Performance
Time frame: Baseline and during both experimental sessions
Working memory performance will be assessed using a cognitive test battery covering different domains of working memory, including visuo-spatial (Spatial Working Memory [SWM], total errors; Paired Associates Learning [PAL], first trial memory score) and verbal-numeric components (Letter Number Sequencing Task [LNST], total score; Letter N-Back Task, discrimination index d'). Individual test scores will be standardized (z-transformation) and combined into a global working memory score according to Vonmoos et al (2013).
5 secondary outcomes
Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP)
Time frame: Baseline and during both experimental sessions
Subjective ratings of current mood and craving
Time frame: Baseline and during both experimental sessions
Adverse effects of the study drug
Time frame: During both experimental sessions
Plasma concentration
Time frame: During both experimental sessions
Heart rate variability
Time frame: During both experimental sessions
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing 4-aminopyridine (4-AP) in people with Cocaine Use Disorder (CUD) and Cognitive Impairments, run by Boris Quednow 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 10 inclusion and 20 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: looking for participants now, as of the sponsor's last update on 17 Aug 2026. 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.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Prof. Dr. rer. nat. Boris B. Quednow, Dr. rer. nat. (+41 58 384 27 77, quednow@bli.uzh.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Global Working Memory Performance (time frame: Baseline and during both experimental sessions). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 17 Aug 2026.