NCT03333668

Experimental fMRI Study of Guanfacine and Lisdexamfetamine in ADHD Adolescents

Experimental fMRI Study on the Comparison of the Brain Function Effects of a Single Dose of Guanfacine and Lisdexamfetamine Relative to Placebo in Children and Adolescents With ADHD.

• Status: Unknown
• Phase: N/A
• Study type: Interventional
• Enrollment: 20 (estimated)
• Sponsor: King's College London · Academic / Other
• Sex: All
• Age: 8 Years – 20 Years
• Healthy volunteers: Accepted

Summary

This is not a clinical trial. The aim of this study is to understand the mechanism of action of two recently licensed drugs for ADHD on brain function. We will compare the brain activation changes elicited by Guanfacine extended release (GXR; a non-stimulant drug) with the brain activation changes elicited by Lisdexamfetamine (LISDEX; a stimulant drug) and by placebo in 20 drug-free patients with ADHD using functional Magnetic Resonance Imaging (fMRI). For this purpose we intend to scan participants during their performance of tasks of attention, working memory, and inhibition, which we know from previous studies to elicit abnormal brain activation patterns in ADHD patients (Rubia et al., 2005; Smith et al., 2006).

Detailed description

Twenty ADHD patients between 8 and 20 years of age will participate in the double-blind, randomised, active drug condition, within-group, placebo-controlled experimental fMRI study. Each participant will be assessed in baseline measures during a pre-assessment visit. Then the patient will be scanned 3 times under each of these 3 drug conditions: GXR, LISDEX, and placebo. Every patient will receive a single typical clinical weight-adjusted dose of GXR (0.05mg/kg rounded down to the closest dose of 1mg, 2mg, or a maximum of 3mg), LISDEX (for participants aged 8-9 years 20mg regardless of weight; for participants aged 10-20 years the dose will be calculated at 0.5mg/kg rounded to the closest 30, 40, or 50mg, middle doses, e.g. 35mg, will be rounded down) and placebo (10mg Vit C) in one of the scans, in a randomised order. Patients will perform a battery of cognitive tests 3.5 hours after drug administration, after which the will undergo an fMRI scan. The scan will start 4.5 hours after drug administration where drugs have shown to have maximum plasma concentration. Participants will be scanned 3 times, one week apart, under each drug condition.

Conditions

• ADHD

Interventions

Type	Name	Description
DRUG	Lisdexamfetamine dimesylate	Lisdexamfetamine dimesylate (30mg for smaller, 50mg for larger boys) tablet
DRUG	Guanfacine Extended Release Oral Tablet	Guanfacine Extended Release (0.05mg/kg) tablet
DRUG	Placebo	Vitamin C (10mg) tablet

Timeline

• Start date: 2018-10-01
• Primary completion: 2022-12-31
• Completion: 2025-03-31
• First posted: 2017-11-07
• Last updated: 2022-08-17

Locations

1 site across 1 country: United Kingdom