The U.S. Food and Drug Administration (FDA) has approved ONYDA XR (clonidine hydrochloride) a once-a-day extended-release oral suspension with nighttime dosing, for the treatment of ADHD as a monotherapy or as an adjunctive therapy to approved central nervous system (CNS) stimulant medications in pediatric patients aged 6 years and older.
The FDA approval was based on two clonidine hydrochloride extended-release ADHD clinical studies (Study 1 and Study 2) that evaluated 256 patients in two 8-week placebo-controlled studies. A third clonidine hydrochloride extended-release ADHD clinical study (Study 3) evaluated 135 pediatric patients 6 to 17 years of age in a 40-week placebo-controlled randomized-withdrawal study.
Study 1 was a short-term, multi-center, randomized, double-blind, placebo-controlled study of two fixed doses (0.2 mg/day or 0.4 mg/day) of clonidine hydrochloride extended-release in pediatric patients 6 to 17 years of age who met DSM-IV criteria for ADHD hyperactive or combined inattentive/hyperactive subtypes. At both doses, improvements in ADHD symptoms were statistically significantly superior in clonidine hydrochloride extended-release-treated patients compared with placebo-treated patients at the end of 5 weeks as measured by the ADHDRS-IV total score. The most common adverse reactions included somnolence, fatigue, irritability, insomnia, nightmare, constipation, dry mouth.
Study 2 was a short-term, randomized, double-blind, placebo-controlled study of a flexible dose of clonidine hydrochloride extended-release as adjunctive therapy to a psychostimulant in pediatric patients 6 to 17 years of age who met DSM-IV criteria for ADHD hyperactive or combined inattentive/hyperactive subtypes, during which clonidine hydrochloride extended-release was initiated at 0.1 mg/day and titrated up to 0.4 mg/day over a 3-week period. Most clonidine hydrochloride extended-release treated patients (75.5%) were escalated to the maximum dose of 0.4 mg/day. ADHD symptoms were statistically significantly improved in clonidine hydrochloride extended-release plus stimulant group compared with the stimulant alone group at the end of 5 weeks as measured by the ADHDRS-IV total score. The most common adverse reactions included somnolence, fatigue, decreased appetite, dizziness.