Clinical Outcomes In Children/Adolescents With Attention-Deficit/Hyperactivity Disorder (ADHD) Receiving Guanfacine Extended Release In Canada: A Retrospective Medical Chart Review

Rationale/Objective: Guanfacine extended release (GXR) has been available in Canada for treatment of ADHD in children/adolescents since 2013. Real-world clinical practice data can provide valuable information for prescribers. The primary objective of this retrospective chart review was to describe changes in clinical outcomes in children/adolescents prescribed GXR for ADHD in Canadian routine clinical practice.

Methods: Children/adolescents (6–17 years) with ADHD prescribed GXR with ≥6 months’ follow-up data were included; chart data were extracted to case report forms (2016–2017). The periods reviewed were ≤12 months pre-GXR and 6–12 months post-GXR initiation. Primary evaluation: change in ADHD symptoms/functionality based on physician assessments, classified as improvement, no change, or worsening for two consecutive visits. Other evaluations: treatment-emergent adverse events (TEAEs; secondary); effectiveness vs prior ADHD pharmacotherapy (exploratory subanalysis).

Results: 330 patients were included (mean[SD] age 10.9[2.6] years); 304 (92.1%) had received prior pharmacotherapy. GXR (mono- [n=60] and adjunctive [n=270] therapy) median(min;max) dose at initiation: 1 (1.0;5.0)mg. While receiving GXR, 232 (70.3%) patients had improvement in symptoms, 16 (4.8%) had no change, and 5 (1.5%) experienced worsening symptoms. School performance improved for 213 (64.5%) and home life for 209 (63.3%) patients. TEAEs were experienced by 147 (44.5%) patients. For patients with no change or worsening symptoms on prior therapy, 37/74 (50.0%) and 44/54 (81.5%), respectively, had improvement of symptoms post-GXR initiation; functionality showed a similar pattern.

Conclusions: In Canadian routine clinical practice, GXR initiation improved ADHD symptoms and functionality in most children and adolescents.

Funding: Shire Development LLC.