The Difference in the Mechanism of Action Between Two Brands of Dexamfetamine in Adults With ADHD

The Difference in Pharmacodynamic and Pharmacokinetic Profiles Between Tentin and Magisterial Dexamfetamine in Adults With Attention Deficit Hyperactivity Disorder, a Double Blinded Randomised Crossover-controlled Trial

The goal of this clinical trial is to compare in the pk/pd profiles of magisterial dexamfetamine and Tentin in adults with Attention Deficit Hyperactivity Disorder (ADHD). The main question[s] it aims to answer are:

Q1: is there a difference between pk/pd profiles of the two forms of dexamfetamine?

Q2: how does the pharmacokinetic variability influences the objective and subjective (side) effects experienced by adult patients with ADHD?

Participants will:

• take the Quantified behavior Test for analysis of objective effects.
• undergo blood sampling for analysis of the plasma concentration of dexamphetamine.
• undergo blood pressure and heart rate measurements.
• fill out 4 types of questionnaires.

Researchers will compare the outcomes between magisterial dexamphetamine and Tentin use in a crossover setting.

Objectives The primary objective is to compare the pharmacological profile of the magisterial form of dexamfetamine sulfate to the pharmacological profile of the brand-name form of dexamfetamine (Tentin©) in adult patients diagnosed with attention deficit hyperactivity disorder (ADHD) and assess whether there is a difference between pk/pd profiles of the two forms of dexamfetamine. The secondary objective is to assess how pharmacokinetic variability influences the objective and subjective (side) effects experienced by adult patients with ADHD.

Measurements At three moments (0, 60 and 120 minutes after drug administration) on each intervention-day, participants will complete the QbTest to assess objective performance and the QbPerformance to assess subjective performance. At eight moments (0, 45, 60, 75, 90, 120, 150 and 180 minutes after drug administration) on each intervention-day, participants will undergo blood sampling to determine dexamfetamine plasma concentrations and vital sign measurements for safety monitoring and possible outcome-effects. At eight moments (0, 45, 60, 75, 90, 120, 150 and 180 minutes after drug administration) on each intervention-day, participants will fill out questionnaires to assess subjective experiences.

Inclusion Criteria:

• Participant is aged ≥ 18 years at time of screening.
• Participant is diagnosed with ADHD according to the DSM 5 criteria.
• Participant has switched from Tentin© to magisterial dexamfetamine due to the adverse effects of Tentin.
• Participant is being treated adequately with dexamphetamine, as determined by their practitioner, at time of screening.
• Participant or their legal representative is able and willing to provide written informed consent.
• Participant is able and willing to comply with the study protocol (e.g. swallow capsules, have blood samples taken, can visit the outpatient clinic twice).
• Participant has not participated in another study in the past three months.

Exclusion Criteria:

• Participant has a disorder that might affect drug absorption (e.g. gastrointestinal, metabolic, endocrine or liver disorder).
• Participant is allergic to the ingredients of the capsules.