An interventional study of 4-aminopyridine (4-AP) and Placebo in Cocaine Use Disorder (CUD) and Cognitive Impairments, sponsored by Boris Quednow. Recruiting at 1 site in Switzerland. Open to participants aged 20 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-08-17.
Sponsored by Boris Quednow · Not applicable, Interventional, and Basic science
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.
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.
3,843 studies on the registry are indexed under Cognitive Dysfunction; 1,100 are open to participants now.
This study's planned enrollment of 40 is below the median of 65 across 2,808 interventional studies indexed under Cognitive Dysfunction.
Browse Cognitive Dysfunction studies →This is the only study on the registry with Boris Quednow as lead sponsor.
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Exclusion Criteria:
Participants receive fampridine (A) in one experimental session and placebo (B) in the other, in the order A then B.
Drug: 4-aminopyridine (4-AP) · Drug: Placebo
Participants receive placebo (B) in one experimental session and fampridine (A) in the other, in the order B then A.
Drug: 4-aminopyridine (4-AP) · Drug: Placebo
Two doses of fampridine administered during one of the two experimental test sessions.
Matching placebo administered during one of the two experimental test sessions.
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).
Time frame: Baseline and during both experimental sessions
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.
Time frame: 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.
Time frame: 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.
Time frame: During both experimental sessions
Plasma concentration
Plasma concentration of the study drug
Time frame: 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.
Time frame: During both experimental sessions
Plan to share: No
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