The Role of Potassium Channels in Working Memory Impairments of Chronic Cocaine Users

Inclusion Criteria: * 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 * 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 Exclusion Criteria: * 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 * 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-compul…