Study of How Trihexyphenidyl Works and Is Processed in Children Ages 5 to 17 With Dystonic Cerebral Palsy to Develop Personalized Dosing

What this Trial Is About

Researchers are studying how the medicine trihexyphenidyl is processed and used in children aged 5 to 17 with dystonic cerebral palsy. This study aims to understand how genetic differences in CYP2D6 and CYP2C19 enzymes affect the way the body breaks down trihexyphenidyl. The information gathered will help design future clinical trials focused on precise dosing for this condition. Participants receive trihexyphenidyl following a specific dose escalation schedule over 16 weeks. For the first 6 weeks, the dose increases from 0.05 mgkg twice daily to 0.25 mgkg three times daily, followed by a 9-week maintenance period at the highest dose. This single-group study evaluates the pharmacokinetics of the drug and the feasibility of future exposure-controlled trials. During the study, participants undergo assessments of drug levels and genetic testing to measure differences in drug metabolism. Researchers monitor dystonia symptoms using several scales, including the Dyskinesia Impairment Scale and Quality of Upper Extremity Skills Test. Safety is tracked through adverse event reports, and caregiver perspectives are also collected. The total study duration for participants is 16 weeks with ongoing recruitment and retention tracked over approximately two years.

Pharmacogenomic Contributions to Trihexyphenidyl Biotransformation and Response in Children With Dystonic Cerebral Palsy